This cheesy loaded meatloaf casserole combines seasoned ground beef with a medley of vegetables for a balanced, high-protein dinner. Packed with melted cheese on top, it's a quick and easy…

Ingredients

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Instructions

Step 1

Preheat your oven to 375°F (190°C). While it heats, prepare your vegetables. Finely dice the onion, zucchini, and red bell pepper into uniform small cubes (about ½ inch). Uniformity ensures they cook evenly and blend seamlessly into the meatloaf texture. Mince the garlic cloves. Thaw the frozen peas and carrots by placing them in a fine-mesh strainer and running cool water over them for a minute; let drain well. Pat all vegetables dry with paper towels to remove excess moisture – this prevents a soggy casserole. Lightly grease a 9×13-inch baking dish or a 2.5-quart casserole dish with cooking spray or a thin layer of olive oil.

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Step 2

In a large mixing bowl, combine the ground beef, diced onion, minced garlic, zucchini, red bell pepper, thawed peas and carrots, tomato sauce, eggs, breadcrumbs (or almond flour), Worcestershire sauce, oregano, smoked paprika, salt, and black pepper. Use your hands (wearing food-safe gloves if preferred) to mix everything together gently but thoroughly. Overmixing can make the meatloaf dense and tough, so stop as soon as the ingredients are evenly distributed. The mixture should be moist but hold together when pressed. If it feels too wet, add an extra tablespoon of breadcrumbs; if too dry, add a splash of tomato sauce.

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Step 3

Transfer the meat mixture into the prepared baking dish and press it into an even layer using a spatula or your hands. Aim for a uniform thickness of about 1 inch to ensure even cooking. Smooth the top slightly. Place the dish in the preheated oven and bake for 25 minutes. The meatloaf should be cooked through but still juicy; an instant-read thermometer inserted into the center should read at least 160°F (71°C). If using a glass dish, note that baking times may vary slightly. While it bakes, you can shred the cheese if not pre-shredded (pre-shredded cheese often contains anti-caking agents that affect melt quality).

Step 4

After 25 minutes, remove the casserole from the oven. Sprinkle the shredded cheddar cheese evenly over the top. Return to the oven and bake for an additional 8-10 minutes, until the cheese is fully melted and bubbly, with golden brown spots developing. For a deeper golden crust, switch the oven to broil for the last 1-2 minutes, watching closely to prevent burning. Let the casserole rest for 5-10 minutes after baking – this allows the juices to redistribute and makes slicing cleaner. Garnish with fresh chopped parsley before serving.

For best results

  • For the best texture, choose lean ground beef with a fat content of 10% or less (90/10 or 93/7). Higher fat content can cause the casserole to become greasy, while extra-lean (96/4) may result in a drier meatloaf. If you only have higher-fat beef, cook the meat with the onions first, drain the fat, then combine with the remaining ingredients. This step adds flavor while controlling grease.
  • To keep the casserole low-carb and gluten-free, substitute the breadcrumbs with almond flour or crushed pork rinds. Almond flour adds a subtle nuttiness and keeps the meatloaf moist. Pork rinds provide a savory crunch. Use a 1:1 ratio by volume. For a keto version, also ensure the tomato sauce is unsweetened and check that no added sugars are present.
  • Vegetable prep is key: after dicing the zucchini and bell pepper, sprinkle them with a little salt and let sit for 10 minutes. Pat dry with paper towels to draw out excess moisture. This step prevents the casserole from releasing too much liquid during baking, which can dilute the flavors and make the dish watery. You can also briefly sauté the vegetables in a dry pan to evaporate moisture.
  • Let the casserole rest after baking for at least 5-10 minutes. This allows the proteins to relax and the juices to redistribute, resulting in a moist, sliceable meatloaf. Cutting too early will cause the juices to run out, leaving a dry casserole. The rest time also helps the cheese set slightly so it doesn't slide off when serving.
  • For meal prep, bake the casserole completely, let it cool, then cut into portions. Store in airtight containers in the refrigerator for up to 4 days. Reheat in the microwave (covered, on medium power) or in a 350°F oven for 10-15 minutes. You can also freeze individual portions for up to 3 months; thaw overnight in the fridge before reheating.
  • If you prefer a firmer, more traditional meatloaf texture, you can shape the mixture into a loaf on a parchment-lined baking sheet and bake it freeform. Then transfer to a casserole dish, top with cheese, and bake until melted. This method promotes better browning on all sides. However, the casserole version is easier and requires less cleanup.
  • Add a smoky depth by including ½ teaspoon of liquid smoke or using smoked cheddar instead of sharp cheddar. Smoked paprika already contributes some smokiness, but liquid smoke amplifies it. For a spicy kick, mix in ¼ teaspoon of cayenne pepper or diced jalapeños with the vegetables.
  • To ensure the casserole holds together well, the eggs act as a binder. If you need an egg-free version, use 2 tablespoons of ground flaxseed mixed with 6 tablespoons of water (let sit for 5 minutes to gel) or ¼ cup of unsweetened applesauce. The texture will be slightly softer but still delicious.

Variations

  • Vegetable Swap: You can substitute the zucchini and bell pepper with other low-moisture vegetables such as finely chopped mushrooms, shredded carrots, or diced asparagus. For mushrooms, sauté them first to release moisture. Avoid watery vegetables like tomatoes or eggplant without pre-cooking. For a Mediterranean twist, add chopped sun-dried tomatoes and olives, and use feta cheese instead of cheddar.
  • Protein Options: Replace ground beef with ground turkey (93/7) or ground chicken for a leaner option. If using ground turkey, add 1 tablespoon of olive oil to the mixture to prevent dryness. For a vegetarian version, use 1½ lbs of cooked lentils or a plant-based ground meat substitute. Increase the breadcrumbs to ¾ cup to help bind the mixture. The cheese can remain or be swapped for a vegan shred.
  • Flavor Twists: Give the casserole a Mexican flair by using taco seasoning (2 tablespoons) instead of oregano and paprika, adding a can of drained black beans, and topping with a blend of cheddar and Monterey Jack cheese. Garnish with sliced jalapeños and a dollop of Greek yogurt. For an Italian version, use Italian seasoning, swap tomato sauce for marinara, and top with mozzarella and Parmesan. Serve with a side of steamed broccoli or a crisp salad.
  • Low-Carb/Keto Adaptation: Omit the breadcrumbs entirely. Increase the almond flour to ½ cup and add ¼ cup of grated Parmesan cheese to the mixture. Use full-fat cheese and ensure all vegetables are low-carb (avoid peas and carrots; use more zucchini, bell pepper, and spinach). The macros will shift significantly, but the dish remains satisfying and high in fat and protein.
  • Add a Crunchy Topping: For extra texture, mix ¼ cup of crushed pork rinds or almond flour with 2 tablespoons of melted butter and sprinkle over the cheese before the final bake. This creates a crispy crust that contrasts beautifully with the tender meatloaf. Alternatively, use crushed pork rinds alone for a keto-friendly crunch.

Nutrition

  • Calories385 kcal
  • Total Fat18g
  • Saturated Fat9g
  • Cholesterol120mg
  • Sodium680mg
  • Total Carbohydrates18g
  • Dietary Fiber4g
  • Sugars7g
  • Protein38g

Common Questions

Can I make this casserole ahead of time?
Yes, you can assemble the entire casserole (without the cheese topping) up to 24 hours in advance. Cover and refrigerate. When ready to bake, add 10-15 extra minutes to the initial bake time since the mixture will be cold. Add the cheese during the last 10 minutes of baking. Alternatively, bake completely, cool, and reheat as directed in the tips.
How do I store leftovers and how long do they last?
Store leftovers in an airtight container in the refrigerator for up to 4 days. For longer storage, freeze individual portions in freezer-safe containers for up to 3 months. Thaw overnight in the refrigerator before reheating. Reheat in the microwave (covered, medium power) for 2-3 minutes or in a 350°F oven for 10-15 minutes.
Can I use a different type of cheese?
Absolutely. Sharp cheddar provides a robust flavor that complements the beef, but you can use Monterey Jack, mozzarella, Gouda, or a Mexican blend. For a stronger flavor, try Gruyère or smoked Gouda. If using a milder cheese, consider adding ¼ cup of grated Parmesan to the meat mixture for extra savoriness.
What can I use instead of breadcrumbs?
Breadcrumbs help bind the meatloaf and absorb excess moisture. For a gluten-free option, use almond flour (1:1 ratio) or crushed pork rinds (1:1). For a grain-free option, use ½ cup of oat flour or ¼ cup of coconut flour (note: coconut flour is more absorbent, so start with less and add more if needed). Quick oats also work but will change the texture slightly.
Why did my casserole turn out watery?
Watery casserole is usually due to excess moisture from vegetables. To prevent this, pat the vegetables dry after dicing, and consider salting and draining zucchini for 10 minutes. Also, avoid overmixing which can break down the meat’s structure and release juices. Using a lean ground beef with less fat also reduces liquid. If you end up with a watery casserole, you can drain off excess liquid before adding the cheese, or thicken with a slurry of 1 tablespoon cornstarch and 2 tablespoons water stirred in before baking.
Can I double this recipe?
Yes, you can easily double the ingredients. Use a larger baking dish (e.g., 9×13 inch for single, 11×17 inch for double) or divide between two dishes. Baking time may increase by 10-15 minutes for a double batch, so check internal temperature. Ensure the dish is not overcrowded to allow even cooking.
Is this recipe suitable for meal prep?
Definitely. This casserole is excellent for meal prep. Divide into 6 servings and store in individual containers. It reheats well and maintains its texture. The flavors often meld and improve after a day in the fridge. Pair with a side of roasted vegetables or a green salad for a complete meal.
What can I serve with this casserole?
This casserole is hearty enough to be a standalone meal, but it pairs wonderfully with a simple side salad dressed with lemon vinaigrette, steamed green beans, roasted asparagus, or cauliflower rice for a low-carb option. For a more traditional meal, serve with mashed potatoes or crusty bread to soak up the juices.