If you are looking for a hearty comfort-food dinner with seasoned ground beef, tender green peppers, a rich creamy sauce, and plenty of melted cheese, this Cheesy Beef & Green Pepper Casserole is an excellent recipe to make. It brings together classic beef-and-pepper flavors in an easy baked casserole that is satisfying without requiring complicated preparation.
The ground beef is cooked with onions, garlic, green bell peppers, Worcestershire sauce, and savory seasonings before being combined with a creamy tomato-cheese sauce. A generous layer of cheddar and mozzarella melts over the top as the casserole bakes, creating a bubbly golden finish.
This recipe is perfect for busy weeknights, potlucks, meal prep, or casual family dinners. Serve it with rice, mashed potatoes, garlic bread, or a crisp salad for a complete meal.
Why You’ll Love This Cheesy Beef & Green Pepper Casserole
The combination of beef, peppers, onions, and melted cheese gives this casserole plenty of classic comfort-food flavor.
Ground beef makes it hearty and filling while green bell peppers provide freshness and a slightly sweet, savory bite.
The creamy tomato sauce keeps the casserole moist and flavorful.
Cheddar provides bold flavor, while mozzarella gives the topping plenty of melt.
It is also easy to customize with pasta, rice, potatoes, mushrooms, bacon, or extra vegetables.
Ingredients
For the Beef and Pepper Filling
- 1½ pounds ground beef
- 1 tablespoon olive oil, if needed
- 1 large green bell pepper, diced
- 1 medium yellow onion, finely diced
- 4 garlic cloves, finely minced
- 2 tablespoons tomato paste
- 1 tablespoon Worcestershire sauce
- 1 teaspoon Dijon mustard
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 1 teaspoon smoked paprika
- 1 teaspoon Italian seasoning
- ¾ teaspoon kosher salt
- ½ teaspoon freshly ground black pepper
- ¼ teaspoon red pepper flakes, optional
For the Creamy Sauce
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- 1 cup low-sodium beef broth
- 1 cup whole milk
- ½ cup sour cream
- ½ cup tomato sauce
- 1 teaspoon Worcestershire sauce
- ½ teaspoon garlic powder
- ½ teaspoon onion powder
- ½ teaspoon freshly ground black pepper
- 1 cup shredded sharp cheddar cheese
For the Cheese Topping
- 1½ cups shredded sharp cheddar cheese
- 1 cup shredded low-moisture mozzarella cheese
- ¼ cup freshly grated Parmesan cheese
Optional Add-Ins
- 8 ounces sautéed mushrooms
- ½ cup crispy crumbled bacon
- 1 cup cooked rice
- 2 cups cooked pasta
- ½ cup corn
- 1 diced jalapeño
For Garnishing
- Fresh parsley
- Sliced green onions
- Extra Parmesan
- Freshly cracked black pepper
How to Make Cheesy Beef & Green Pepper Casserole
1. Preheat the Oven
Preheat your oven to 375°F (190°C).
Lightly grease a 9×13-inch baking dish.
2. Heat the Skillet
Place a large skillet over medium-high heat.
Add olive oil if your ground beef is particularly lean.
3. Brown the Ground Beef
Add the beef.
Break it into small crumbles with a wooden spoon or spatula.
Cook for approximately 6–8 minutes, until browned and fully cooked.
Ground beef should reach 160°F (71°C).
4. Add the Onion
Stir in the diced onion.
Cook for approximately 3–4 minutes, until beginning to soften.
5. Add the Green Pepper
Add the diced green bell pepper.
Cook for another 3–4 minutes.
The pepper should soften slightly but retain some texture.
6. Add the Garlic
Stir in the minced garlic.
Cook for approximately 30–60 seconds, just until fragrant.
7. Drain Excess Grease
If necessary, carefully drain most of the excess fat from the skillet.
8. Add Tomato Paste
Stir in the tomato paste.
Cook for approximately 1–2 minutes.
This develops a deeper tomato flavor.
9. Season the Beef
Add:
- Worcestershire sauce
- Dijon mustard
- Garlic powder
- Onion powder
- Smoked paprika
- Italian seasoning
- Salt
- Black pepper
- Red pepper flakes, if using
Mix thoroughly.
10. Cook Briefly
Continue cooking for approximately 2 minutes.
Transfer the beef-and-pepper mixture to a bowl if you need the same skillet for the sauce.
11. Melt the Butter
Reduce the heat to medium.
Add the butter.
12. Add the Flour
Sprinkle in the flour.
Whisk continuously for approximately 1–2 minutes.
13. Add Beef Broth
Slowly pour in the beef broth while whisking.
Continue until smooth.
14. Add Milk
Gradually pour in the milk.
Whisk until completely combined.
15. Add Tomato Sauce
Stir in the tomato sauce.
16. Season the Sauce
Add:
- Worcestershire sauce
- Garlic powder
- Onion powder
- Black pepper
17. Simmer
Cook over medium-low heat for approximately 3–5 minutes, stirring frequently.
The sauce should begin to thicken.
18. Add Sour Cream
Reduce the heat to low.
Stir in the sour cream until smooth.
19. Add Cheddar
Gradually add 1 cup shredded cheddar.
Stir until melted.
Do not let the sauce boil aggressively after adding the cheese.
20. Return the Beef Mixture
Add the beef, peppers, and onions back to the skillet.
Stir until everything is evenly coated.
21. Add Optional Ingredients
If using rice, cooked pasta, mushrooms, corn, or bacon, stir them in now.
22. Transfer to the Baking Dish
Spoon the mixture evenly into the prepared baking dish.
23. Add Cheddar
Sprinkle the cheddar evenly over the top.
24. Add Mozzarella
Add the mozzarella.
25. Add Parmesan
Finish with Parmesan.
26. Cover
Cover loosely with foil.
27. Bake Covered
Bake for approximately 15–20 minutes.
28. Uncover
Remove the foil.
29. Continue Baking
Bake for another 10–15 minutes.
The casserole should be bubbling around the edges and the cheese fully melted.
30. Broil for Extra Browning
For a golden cheese topping, broil for approximately 1–2 minutes.
Watch carefully.
31. Rest
Remove the casserole from the oven.
Let it rest for approximately 5–10 minutes.
32. Garnish
Finish with parsley, green onions, Parmesan, or cracked black pepper.
33. Serve
Spoon generous portions onto plates and serve hot.
What to Serve With Cheesy Beef & Green Pepper Casserole
This casserole pairs especially well with:
- Garlic mashed potatoes
- White rice
- Buttered noodles
- Roasted potatoes
- Garlic bread
- Dinner rolls
For vegetables or lighter sides, try:
- Garden salad
- Caesar salad
- Roasted broccoli
- Green beans
- Garlic asparagus
- Brussels sprouts
Tips for the Best Beef & Green Pepper Casserole
Drain excess grease from the ground beef.
Do not overcook the peppers before baking.
Cook the tomato paste briefly for deeper flavor.
Use freshly shredded cheese for smoother melting.
Keep the sauce slightly loose before baking.
Add sour cream over low heat.
Do not aggressively boil the cheese sauce.
Bake covered first to retain moisture.
Broil only briefly.
Let the casserole rest before serving.
Easy Recipe Variations
Philly Cheesesteak-Style Casserole
Add:
- Mushrooms
- Extra onions
- Provolone cheese
Use less tomato sauce for a more cheesesteak-style flavor.
Cheesy Beef & Rice Casserole
Stir in 2 cups cooked rice before baking.
Beef & Pepper Pasta Bake
Add 10–12 ounces cooked penne or rotini.
Increase the sauce slightly if needed.
Bacon Cheeseburger Pepper Casserole
Add:
- Crispy bacon
- Pickles after baking
- Extra cheddar
- A little ketchup and mustard
Spicy Beef Pepper Casserole
Add:
- Jalapeños
- Red pepper flakes
- Pepper Jack cheese
Mushroom Beef Casserole
Add 8 ounces sliced mushrooms.
Cook them until browned and their excess moisture evaporates.
Three-Cheese Version
Use:
- Cheddar
- Mozzarella
- Provolone
Low-Carb Version
Skip pasta and rice and increase the beef, peppers, mushrooms, or cauliflower.
How to Store Leftovers
Allow leftover casserole to cool before transferring it to an airtight container.
Refrigerate for up to 3–4 days.
Reheating in the Oven
Place leftovers in a covered baking dish.
Add a splash of beef broth or milk if necessary.
Reheat at 350°F (175°C) until hot.
Reheating in the Microwave
Microwave individual portions in short intervals.
Stir gently if possible.
Freezing
This casserole can be frozen.
For best results, assemble it but do not bake.
Cover tightly and freeze for up to approximately 2 months.
Thaw overnight in the refrigerator before baking.
Frequently Asked Questions
Can I use red or yellow bell peppers?
Yes. You can replace some or all of the green pepper with red, yellow, or orange bell peppers for a sweeter flavor.
Can I add rice?
Absolutely. About 2 cups of cooked rice turns this into an especially hearty casserole.
Can I add pasta?
Yes. Penne, rotini, shells, or rigatoni work very well.
Can I make this ahead?
Yes. Assemble the casserole up to a day ahead, cover, and refrigerate until ready to bake.
Can I use ground turkey instead of beef?
Yes. Ground turkey works well and should be cooked to 165°F (74°C).
Why is my casserole watery?
The beef may not have been drained thoroughly, or vegetables such as mushrooms may have released excess moisture. Cook watery ingredients before assembling.
What cheese works best?
Sharp cheddar provides strong flavor, while mozzarella, provolone, Monterey Jack, and Parmesan are excellent additions.
Can I add mushrooms?
Yes. Sauté them first until well browned and their moisture has evaporated.
Final Thoughts
This Cheesy Beef & Green Pepper Casserole combines savory ground beef, tender bell peppers, onions, garlic, creamy tomato-cheddar sauce, mozzarella, and Parmesan in one easy baked dinner.
The key is browning the beef well, keeping some texture in the peppers, and making the cheese sauce slightly loose before baking so the casserole stays creamy rather than dry.
Serve it with mashed potatoes, rice, pasta, or garlic bread for a comforting family meal that is beefy, cheesy, and packed with savory pepper flavor.