Cheesy Ground Beef, Mushroom & Pepper Casserole
This hearty, cheesy casserole is inspired by the dish in your photo. It combines seasoned ground beef, mushrooms, bell peppers, tomato sauce, and plenty of melted cheese for a comforting, family-friendly meal.
Prep Time
15 minutes
Cook Time
30–35 minutes
Total Time
45–50 minutes
Servings
8 servings
Ingredients
For the Beef Mixture
2 lb (900 g) lean ground beef
1 medium onion, finely diced
3 cloves garlic, minced
8 oz (225 g) mushrooms, sliced
1 red bell pepper, diced
1 green bell pepper, diced
1 tbsp olive oil
1 tsp Italian seasoning
1 tsp paprika
½ tsp garlic powder
½ tsp onion powder
½ tsp salt, or to taste
¼ tsp black pepper
½ tsp red pepper flakes, optional
For the Sauce
2 cups (480 g) low-sugar marinara or tomato sauce
2 tbsp tomato paste
½ tsp Italian seasoning
¼ tsp black pepper
For the Cheesy Topping
2 cups shredded mozzarella cheese
1 cup shredded cheddar cheese
½ cup grated Parmesan cheese
1–2 tbsp chopped fresh parsley
Optional: extra diced red pepper for topping
Instructions
1. Prepare the oven
Preheat your oven to 375°F (190°C).
Lightly grease a 9×13-inch baking dish.
2. Brown the beef
Heat the olive oil in a large skillet over medium-high heat.
Add the ground beef and cook for 6–8 minutes, breaking it apart with a wooden spoon, until browned and cooked through.
Drain excess grease if necessary.
3. Add the vegetables
Add the diced onion, garlic, mushrooms, red bell pepper, and green bell pepper.
Cook for 6–8 minutes, stirring occasionally, until the vegetables soften and the mushrooms release most of their moisture.
4. Season
Add Italian seasoning, paprika, garlic powder, onion powder, salt, black pepper, and optional red pepper flakes.
Stir well and cook for another 1–2 minutes.
5. Add the sauce
Stir in the marinara sauce and tomato paste.
Simmer for 5 minutes, allowing the flavors to combine.
Taste and adjust the seasoning.
6. Assemble
Transfer the beef and vegetable mixture to the prepared baking dish.
Spread it evenly.
Sprinkle the mozzarella and cheddar over the top, followed by the Parmesan.
Add a little extra diced red pepper and parsley if desired.
7. Bake
Bake uncovered for 20–25 minutes, until the cheese is completely melted and bubbling.
For a more golden top, switch the oven to broil for 1–2 minutes at the end. Watch carefully so the cheese doesn’t burn.
8. Rest and serve
Remove from the oven and let the casserole rest for 5–10 minutes before serving.
Garnish with fresh parsley.
Nutrition Information
Approximate per serving, based on 8 servings:
Calories: 475 kcal
Protein: 36 g
Fat: 32 g
Saturated Fat: 15 g
Carbohydrates: 11 g
Fiber: 2 g
Net Carbs: 9 g
Sugars: 5 g
Cholesterol: 105 mg
Sodium: 750 mg
Nutrition will vary depending on the ground beef, cheese, and marinara sauce used.
Naturally Gluten-Free
The ingredients listed are naturally gluten-free, but check the labels on your marinara sauce, seasonings, and shredded cheese if you need to avoid gluten strictly.
Lower-Carb Option
For fewer carbohydrates, use a no-sugar-added marinara sauce, reduce the onion, and add extra mushrooms, spinach, or zucchini.
Higher-Protein Option
Use very lean ground beef and add ½–1 lb ground turkey or chicken if you want to increase the protein while keeping the casserole hearty.
Easy Variations
Pizza Style: Add pepperoni, Italian sausage, olives, and extra mozzarella.
Taco Style: Replace Italian seasoning with taco seasoning and use cheddar + Monterey Jack.
Chicken Version: Substitute cooked shredded chicken for the ground beef.
Vegetable Version: Replace the beef with extra mushrooms, zucchini, spinach, and cauliflower.
Spicy Version: Add jalapeños and extra red pepper flakes.
Recipe Q&A
Q: Can I make this casserole ahead of time?
A: Yes. Assemble the casserole, cover it, and refrigerate for up to 24 hours. Bake when ready, adding a few extra minutes if it is cold from the refrigerator.
Q: Can I freeze it?
A: Yes. Cool completely, cover tightly, and freeze for up to 2–3 months. Thaw overnight in the refrigerator before reheating.
Q: Can I use ground turkey instead of beef?
A: Absolutely. Ground turkey makes a lighter version while still providing plenty of protein.
Q: What cheese works best?
A: Mozzarella gives you the stretchy melted cheese seen in the photo, while cheddar adds stronger flavor. Monterey Jack or provolone also work well.
Q: Can I make it without mushrooms?
A: Yes. Simply leave them out and add extra bell peppers, zucchini, spinach, or another vegetable.
Q: Is this keto-friendly?
A: It can fit a keto-style meal when prepared with a low-carb/no-sugar-added marinara and portions of onion and peppers are kept moderate. Check the nutrition label of your sauce and cheese.
Q: How do I keep the casserole from becoming watery?
A: Cook the mushrooms and vegetables until most of their moisture has evaporated before adding the sauce. Also avoid adding watery vegetables without sautéing them first.
Q: How do I store leftovers?
A: Refrigerate in an airtight container for up to 3–4 days.
Q: How should I reheat it?
A: Microwave individual portions for 1–2 minutes, or reheat covered in a 350°F (175°C) oven until hot.
Q: Can I add pasta?
A: Yes. Stir in about 3–4 cups cooked pasta before baking for a traditional cheesy pasta casserole. The nutrition information will change.
Serving Ideas
Serve this casserole with:
Green salad
Roasted broccoli
Cucumber salad
Steamed vegetables
Avocado salad
Garlic bread for a higher-carb option
