High-Protein Zucchini & Beef Casserole

Quick Description
This High-Protein Zucchini & Beef Casserole is a savory, cheesy dish packed with lean ground beef, fresh zucchini, and bell peppers, all topped with melted cheese for a comforting, filling meal.
Servings & Timing
Servings: 6
Prep Time: 10 minutes
Cook Time: 30–35 minutes
Total Time: ~45 minutes
Ingredients List
Casserole
- 1 lb lean ground beef (90% lean or higher)
- 2 medium zucchini, thinly sliced
- 1 bell pepper, diced
- 1 small onion, diced
- 2 cloves garlic, minced
- 1 cup marinara sauce (low-sugar)
- 1 ½ cups shredded mozzarella cheese
- ½ cup grated Parmesan cheese
- 4 large eggs
- 1 tbsp olive oil
- Salt & pepper, to taste
Step-by-Step Instructions
Step 1: Preheat the Oven
Preheat your oven to 375°F (190°C) and grease a 9×9-inch baking dish.
Step 2: Cook the Ground Beef
In a large skillet, heat olive oil over medium heat. Add diced onion, bell pepper, and garlic, cooking until softened, about 5 minutes. Add the ground beef, breaking it apart with a spatula. Cook until browned. Drain any excess fat.
Step 3: Layer the Casserole
In the baking dish, spread a layer of zucchini slices. Top with the cooked ground beef mixture, followed by another layer of zucchini. Pour marinara sauce evenly over the zucchini.
Step 4: Prepare the Egg Mixture
In a bowl, whisk the eggs, salt, and pepper until well combined. Pour the egg mixture evenly over the casserole.
Step 5: Bake
Top with shredded mozzarella and grated Parmesan. Bake in the preheated oven for 30–35 minutes, or until the casserole is set and golden on top.
Step 6: Serve
Allow the casserole to cool for 5 minutes before slicing. Serve hot!
Additional Notes
- For extra protein, add some cottage cheese to the ground beef mixture or sprinkle with a bit more cheese before baking.
- For a lower-carb option, use zucchini noodles (zoodles) instead of sliced zucchini.
Dietary Info
High-Protein
Low-Carb
Gluten-Free
Weight-Loss Friendly
Ingredient Details & Substitutions
- Ground Beef: Ground turkey or chicken can be used for a leaner option.
- Zucchini: Yellow squash can be used as an alternative to zucchini.
- Cheese: Use reduced-fat cheese to lower the fat content.
Recipe Variations & Serving Suggestions
- Spicy Beef & Zucchini: Add red pepper flakes or chili powder to the ground beef for some heat.
- Vegetarian Version: Replace the ground beef with lentils or mushrooms for a plant-based version.
- Serve With: A side salad or steamed vegetables for extra nutrients.
Storage & Make-Ahead
Fridge: 3–4 days
Freezer: Up to 2 months
Reheat in the microwave or oven for best results.
Nutrition (Per Serving – Approximate)
Calories: 280–350
Protein: 30–35 g
Carbs: 10–12 g
Fat: 18–22 g
Sugar: 4–6 g
Optional Personal Story
This casserole is a great way to use up summer zucchini and get in a healthy, filling meal with plenty of protein. It’s a go-to for me whenever I’m craving something hearty but light.