This high-protein cheesy taco casserole is a one-pan favorite loaded with seasoned ground beef, colorful peppers, tomatoes, and plenty of melted cheese. Every serving delivers 28 g of protein and only 5 g net carbs for a satisfying taco-night dinner without the carbs.
Completely sugar-free, low-carb, and perfect for busy weeknights or meal prep.
Why you’ll love this casserole
- 28g protein per serving — a complete high-protein meal
- Only 5g net carbs and fully sugar-free
- Classic taco flavors with melted cheese on top
- Ready in about 30 minutes
- One baking dish, easy cleanup
- Excellent for meal prep and leftovers
Health notes
- High protein: Ground beef and cheese provide a solid protein base.
- Low carb: Peppers, tomatoes, and no tortillas keep net carbs low.
- Sugar-free: Use a sugar-free taco seasoning or homemade blend.
- Family-friendly: Kid-approved flavors in a convenient casserole form.
Key element — drain the beef well
After browning the ground beef, drain excess fat thoroughly. This keeps the casserole from becoming greasy and helps the flavors stay clean and balanced.
Ingredients
Beef mixture
- 1½–2 lb (680–900g) lean ground beef (90% lean or higher preferred)
- 1 medium onion, diced
- 1 red bell pepper, diced
- 1 green bell pepper, diced
- 2–3 garlic cloves, minced
- 1–2 Tbsp taco seasoning (sugar-free) or homemade blend
- 1 cup diced tomatoes (fresh or canned, drained)
- Salt and black pepper to taste
Cheese & toppings
- 2–2½ cups shredded Mexican blend, cheddar, or mozzarella cheese
- Optional: ½ cup cream cheese or sour cream stirred into the beef
- Fresh cilantro or green onion for garnish
Homemade taco seasoning (optional)
- 1 Tbsp chili powder
- 1 tsp cumin
- 1 tsp paprika
- ½ tsp garlic powder
- ½ tsp onion powder
- ½ tsp oregano
- Salt and cayenne to taste
Swaps
- Turkey or chicken: Use ground turkey or chicken for a leaner version.
- Extra veggies: Add zucchini, cauliflower rice, or spinach.
- Spicy: Add diced jalapeños or extra cayenne.
- Dairy-free: Use a dairy-free shredded cheese alternative.
Instructions
| 1 | Preheat and brown the beef. Preheat oven to 375°F (190°C). In a large skillet over medium-high heat, cook the ground beef until browned, breaking it up as it cooks. Drain excess fat thoroughly. |
| 2 | Add vegetables and seasoning. Add the diced onion, bell peppers, and garlic to the skillet. Cook 4–5 minutes until softened. Stir in the taco seasoning, diced tomatoes, salt, and pepper. Cook 2–3 minutes more until fragrant and slightly thickened. Taste and adjust seasoning. |
| 3 | Assemble the casserole. Transfer the beef mixture to a lightly greased 9×13-inch baking dish (or similar). Spread evenly. Sprinkle the shredded cheese evenly over the top. |
| 4 | Bake. Bake 12–15 minutes until the cheese is melted and bubbly. For extra browning, broil the last 1–2 minutes while watching closely. |
| 5 | Rest and serve. Let the casserole rest 3–5 minutes. Garnish with cilantro or green onion if desired and serve hot. |
Pro tips
- Drain the beef well so the casserole stays flavorful without excess grease.
- Use a sugar-free taco seasoning or make your own to keep it fully sugar-free.
- For creamier texture, stir a few tablespoons of cream cheese or sour cream into the beef mixture before baking.
- This reheats excellently and is ideal for meal-prep lunches.
- Serve with a simple side salad, avocado, or cauliflower rice for a complete low-carb meal.