Oven Baked 3-Ingredient Chili Mac Casserole: The Easiest Weeknight Dinner You’ll Ever Make

Servings: 6–8 | Prep time: 10 minutes | Bake time: 30–35 minutes | Rest time: 10 minutes | Total time: About 50 minutes

Let me tell you about a dinner that has no business being this delicious with only three ingredients. Canned chili. Dry elbow macaroni. Sharp cheddar cheese. That’s it. No chopping. No browning meat. No simmering sauce. Just three simple ingredients transformed into a bubbling, cheesy, deeply satisfying casserole that tastes like you spent all afternoon in the kitchen.

This Oven Baked 3-Ingredient Chili Mac Casserole is the ultimate weeknight hero.

It’s budget-friendly (canned chili and pasta cost pennies). It’s pantry-stable (you can make it anytime, no fresh ingredients required). It’s kid-approved (macaroni and cheese meets chili). And it’s so easy that even a beginner cook can nail it on the first try.

The secret is in the technique. Par-boiling the pasta so it stays firm. Mixing everything while it’s still hot. Tenting with foil to trap steam without sticking to the cheese. And that final uncovered bake to create those gorgeous, caramelized, nutty brown spots on top.

Serve it with a side salad or some crusty bread, and you’ve got a complete meal that will disappear before you know it.

Why You’ll Love This Recipe

Only three ingredients – Canned chili, macaroni, cheddar cheese.
No chopping, no browning, no simmering – Open, boil, mix, bake.
Budget-friendly – This whole casserole costs less than takeout for one person.
Pantry meal – Everything is shelf-stable (except the cheese, which lives in the fridge).
Kid-approved – Mac and cheese meets chili. What’s not to love?
Perfect for busy weeknights– 10 minutes of active prep, then the oven does the work.
Great for potlucks and game day – Travels well and feeds a crowd.

Ingredients

Beef chili (canned or leftover) – 4 cups (about two 15-ounce cans)
Dry elbow macaroni – 12 ounces (about 3 cups dry)
Sharp cheddar cheese (shredded, divided) – 3 cups

Ingredient Notes

What kind of canned chili? Any canned beef chili works. Use your favorite brand — Homestyle, no-bean, with beans, spicy, or mild. If you use chili with beans, you’ll get extra texture and fiber. If you use no-bean chili, the casserole will be more mac-and-cheese-forward. Leftover homemade chili is fantastic here too.

What if I don’t have 4 cups of chili?Use two 15-ounce cans (about 3¾ cups) — close enough. Or supplement with a can of tomato sauce and an extra sprinkle of chili powder.

What kind of pasta? Elbow macaroni is traditional, but small shells, cavatappi, or any short tube pasta works. Avoid long noodles (spaghetti, fettuccine) — they won’t distribute evenly.

What kind of cheddar? Sharp cheddar provides the most flavor. Mild cheddar works but is less pronounced. Freshly shredded cheese melts more smoothly than pre-shredded (which contains anti-caking agents). If using pre-shredded, expect a slightly grainier texture — it will still taste great.

Can I add other cheeses?Absolutely. Try adding:

Monterey Jack – Creamy and mild
Pepper Jack – For a spicy kick
Colby Jack – Similar to cheddar but milder
Parmesan – Sprinkle on top for a nutty finish

Step-by-Step Directions

Step 1: Preheat and Par-Boil

Preheat your oven to 375°F (190°C) .

Bring a large pot of salted water to a rolling boil. Add the 12 ounces of dry elbow macaroni and cook for 1½ to 2 minutes less than the package directions.

Why this matters (the “mechanical” step): If you cook the pasta to full tenderness on the stove, it will become mushy after 30–35 minutes in the oven. Keeping it firm ensures it holds its shape against the heavy chili and cheese. The pasta will finish cooking in the casserole.

Drain the macaroni well. Do not rinse — you want the starch to help thicken the casserole.

Step 2: The Pot Mix

Return the drained macaroni to the warm pot (off the heat). Stir in:

4 cups of beef chili
2 cups of shredded sharp cheddar cheese (reserve 1 cup for the top)

Stir until the mixture is glossy and the cheese begins to pull into strings. The residual heat from the pasta and pot will start melting the cheese.

The Texture Rule: If the mixture looks too dry, add a small splash of water or beef broth (about ¼ cup). You want it “saucy” because the pasta will continue to absorb liquid as it bakes. A dry-looking casserole going into the oven will come out dry and pasty.

Step 3: The Even Layer

Pour the mixture into a 9×13-inch baking pan (a disposable foil pan works great for easy cleanup). Spread it evenly into the corners.

Sprinkle the remaining 1 cup of shredded sharp cheddar cheeseevenly over the top.

Step 4: The Tented Bake

Cover the pan loosely with aluminum foil, tenting it so the foil doesn’t touch the cheese. If the foil touches the cheese, the cheese will stick to the foil and pull off when you remove it.

Bake for 20 minutes with the foil on.

Remove the foil and bake for another 10 to 15 minutesuncovered, until the cheese is bubbly and developing small, toasted brown spots.

Why the uncovered finish matters:Those small, toasted brown spots on the cheese indicate caramelization — the sugars in the cheese are browning, creating a deep, nutty, savory flavor. This is what takes the casserole from “good” to “great.”

Step 5: The Essential Rest

Remove the casserole from the oven. Let it rest for 10 minutes before serving.

Why rest matters:This rest allows the starches in the pasta to “bond” with the fats in the cheese and chili. Slicing in too early will result in the chili running to the bottom of the pan and the casserole falling apart. Waiting 10 minutes ensures a cohesive, scoopable meal that holds its shape on the plate.

Step 6: Serve

Scoop into bowls and serve hot. Garnish with fresh parsley, sliced green onions, or a dollop of sour cream if desired.

Variations & Tips

Make It Spicy

Use spicy chili (look for “hot” or “spicy” on the can)
Add 1 teaspoon of cayenne pepperto the chili mixture
Stir in ½ cup of diced pickled jalapeños
Top with sliced fresh jalapeñosbefore the final bake
Use Pepper Jack cheeseinstead of or in addition to cheddar

Add Vegetables

Stir in any of these along with the chili:

1 cup frozen corn (no need to thaw)
1 cup diced bell peppers(any color)
1 can (4 oz) diced green chiles
1 cup frozen peas and carrots

Make It Creamier

Stir in ½ cup of sour creamor cream cheese along with the chili
Use half cheddar, half Velveeta for an ultra-creamy texture
Add ½ cup of heavy cream if the mixture seems dry

Make It with Homemade Chili

Leftover homemade chili is fantastic here. Use any beef chili recipe — or even turkey chili, white chicken chili, or vegetarian chili. Just make sure you have about 4 cups.

Make It with Ground Beef (No Canned Chili)

Brown 1 pound of ground beef with 1 small diced onion and 2 cloves of garlic. Add 1 can (15 oz) of tomato sauce, 1 can (15 oz) of diced tomatoes (undrained), 2 tablespoons of chili powder, 1 teaspoon of cumin, and salt to taste. Simmer for 10 minutes. Proceed with the recipe.

Make It Gluten-Free

Use gluten-free elbow macaroni(cook according to package directions, still par-boiling by 1–2 minutes). Check that your canned chili is gluten-free (most are, but check the label).

Make It in a Skillet (Stovetop Only)

Cook the macaroni as directed.
In a large oven-safe skillet, combine the drained macaroni, chili, and 2 cups of cheese.
Top with remaining cheese.
Cover and cook over medium-low heat for 10 minutes until cheese melts.
(Optional) Transfer to the oven to brown the top.

Storage & Reheating

Refrigerator: Store leftovers in an airtight container for up to 5 days. The casserole will firm up as it cools — that’s normal.

Reheating:

Microwave: 1–2 minutes per serving. Add a splash of water or broth if it seems dry.
Oven: 350°F for 10–15 minutes, covered with foil to prevent drying out.
Skillet: Warm over medium-low heat, stirring occasionally, adding a splash of water or broth as needed.

Freezing: This casserole freezes beautifully for up to 3 months. Assemble the casserole completely but do not bake. Wrap tightly with foil and freeze. Bake from frozen at 375°F for 45–50 minutes (covered for the first 30 minutes, uncovered for the last 15–20). You can also freeze baked leftovers — just thaw overnight before reheating.

Frequently Asked Questions (FAQs)

Can I use leftover chili from the fridge?

Absolutely. Leftover homemade chili is even better than canned. Use 4 cups of leftover chili. If it’s very thick, add a splash of water or broth to loosen it before mixing with the pasta.

Can I use a different pasta shape?

Yes. Small shells, cavatappi (corkscrew), rotini, or penne all work well. Avoid long noodles (spaghetti, fettuccine, linguine) — they won’t distribute evenly and will clump together. Adjust cooking time based on the package directions, still par-boiling by 1–2 minutes.

Why is my casserole dry?

A few possibilities:

Your chili was very thick (add a splash of water or broth next time)
You overbaked it (check at 30 minutes total bake time)
You used lean or low-fat cheese (doesn’t melt as creamy)
You didn’t add enough chili (measure 4 cups)

Why is my casserole watery?

A few possibilities:

Your chili was very thin (add less next time, or simmer to thicken)
You added too much water or broth
You didn’t drain the pasta well (excess water on the noodles)
You undercooked the pasta (releases more starch as it finishes baking)

Can I double this recipe?

Yes. Use a larger baking dish (10×15-inch or two 9×13-inch pans). Double all ingredients. Bake time may increase by 5–10 minutes. Check for doneness when the cheese is bubbly and browned.

Can I make this in a slow cooker?

Yes, but the texture will be different (softer, less caramelized). Cook the pasta fully (not par-boiled) and combine all ingredients in the slow cooker. Cook on LOW for 2–3 hours or HIGH for 1–2 hours. For a crispy top, transfer to a baking dish and broil for 2–3 minutes before serving.

Can I use non-dairy cheese?

Yes. Use your favorite dairy-free shredded cheddar. The texture will be different (it may not melt as smoothly), and the flavor will vary by brand. Daiya, Violife, and Follow Your Heart all work reasonably well.

What to Serve With It

This casserole is a complete meal on its own, but here are some pairing ideas:

For a simple dinner:

Side salad – With ranch or Italian dressing
Steamed green beans or broccoli – Adds color and crunch
Crusty bread – For sopping up any leftover chili sauce

For game day or potlucks:

Cornbread – Sweet and crumbly
Coleslaw – Creamy or vinegar-based
Pickles or pickled vegetables – Bright and acidic to cut the richness

For toppings (let people customize):

Sour cream
Sliced green onions
Fresh cilantro
Hot sauce (Tabasco, Cholula, or Sriracha)
Diced fresh tomatoes
Sliced black olives

Why This 3-Ingredient Recipe Works

You might be skeptical — three ingredients? That can’t be that good. But here’s why it works:

Canned chili is already a complete flavor base. It has seasoned beef, tomatoes, beans (if you use that kind), and a blend of chili spices. You’re not starting from scratch — you’re starting from delicious.

Elbow macaroni provides the perfect texture. Its small, curved shape holds onto the chili and cheese, and it cooks evenly in the casserole.

Sharp cheddar cheese adds sharpness, creaminess, and that glorious browned top. It bridges the chili and pasta, creating a cohesive, scoopable casserole.

The techniques — par-boiling, tenting, resting — are what elevate this from “dump and bake” to genuinely good. Follow those steps, and you’ll have a casserole that tastes like you put in way more effort than you actually did.

Final Thoughts

This Oven Baked 3-Ingredient Chili Mac Casserole is proof that dinner doesn’t need to be complicated to be delicious. Three ingredients. One pan. About 50 minutes. And a meal that will have everyone asking for seconds — and the recipe.

Keep canned chili, a box of macaroni, and a bag of shredded cheddar in your pantry at all times. You’re never more than an hour away from a hot, satisfying, crowd-pleasing dinner.

Make it on a busy Tuesday. Make it for a potluck. Make it when you’re staring into the fridge and nothing looks good. Just make it. You’ll be glad you did.