Ingredients
Ground Beef
90/10 or 93/7 lean ground beef is the target. At these fat percentages, there’s enough fat to develop good browning and flavor without producing a pool of grease that needs to be drained excessively and makes the filling greasy.
If you prefer alternatives: ground turkey (94/6 or leaner) produces a slightly milder, lighter result with similar protein content. Ground chicken works similarly. Ground bison is an excellent choice — leaner than beef with a slightly richer, earthier flavor that works beautifully with the pepper and cheese profile.
Bell Peppers
The recipe uses one green and one red bell pepper for visual contrast and complementary flavor. Red bell peppers are sweeter and fruitier — fully ripened versions of the same pepper as the green, which are harvested earlier and have a sharper, more vegetal flavor. Together they provide balance. Yellow and orange bell peppers are equally appropriate substitutes or additions.
Mushrooms
White button or cremini mushrooms both work. Cremini (baby bella) mushrooms have a slightly deeper, earthier flavor that adds more complexity to the filling. Slice them approximately ¼ inch thick so they cook evenly and contribute satisfying texture rather than disappearing into the filling.
Don’t skip the mushrooms. They add umami depth that makes the overall dish taste more complex and satisfying, and they stretch the filling volume while adding minimal calories.
Cottage Cheese
Low-fat (2%) cottage cheese is specified and works best. Full-fat cottage cheese adds unnecessary richness to a dish that’s already rich from the beef and cheese. Fat-free cottage cheese can produce a slightly drier, grainier result. Small curd and large curd both blend to the same smooth consistency — use whichever you have.
Greek Yogurt
Plain, full-fat or 2% Greek yogurt is the right choice. Flavored yogurts are obvious non-starters. Fat-free Greek yogurt is acceptable but produces a slightly tangier, slightly drier result than 2%.
Provolone
Sharp provolone melts beautifully and has more flavor than mild provolone. If you can find it sliced from a deli block rather than pre-shredded, use it — the flavor and melt quality are both better. Shredded provolone works perfectly well.
Instructions
Preheat the oven to 375°F (190°C). Grease a 9×13-inch baking dish with cooking spray or a thin coat of olive oil. Dice all the vegetables, slice the mushrooms, and mince the garlic before you start cooking — this casserole moves quickly once the skillet is hot.
Heat a large skillet over medium-high heat. Add the ground beef and cook for 6 to 8 minutes, breaking it into crumbles with a wooden spoon or spatula. The goal is properly browned beef with some caramelized color on the exterior — not gray, steamed meat. If the pan looks crowded, let the beef cook undisturbed for 2 to 3 minutes before stirring to develop color.
Drain any accumulated fat. Lean ground beef typically produces minimal fat; fattier blends may require more thorough draining. Excess fat in the filling can prevent the casserole from setting properly.
Add the diced onion, green bell pepper, red bell pepper, and sliced mushrooms to the skillet with the beef. Cook over medium-high heat for 5 to 6 minutes, stirring occasionally, until the vegetables are softened and any liquid the mushrooms release has mostly evaporated. Add the minced garlic and cook for 30 seconds, stirring constantly.
Add the Worcestershire sauce, onion powder, garlic powder, smoked paprika, Italian seasoning, salt, and black pepper. Stir to coat everything evenly. Taste at this point and adjust seasoning — the beef and vegetable mixture should taste well-seasoned and slightly salty, as the cheese and dairy will dilute the seasoning somewhat.
Remove from heat.
In a large mixing bowl, whisk together the cottage cheese and Greek yogurt until the mixture is as smooth as possible — the curds won’t fully disappear through whisking alone, but breaking them down as much as possible produces the best final texture. For an entirely smooth base, blend briefly with an immersion blender or standard blender.
Stir in the 1½ cups of shredded provolone and 1 cup of shredded mozzarella. The mixture will be thick and cheesy.
Fold the beef and vegetable mixture into the cheese base until everything is evenly distributed — every spoonful should contain beef, vegetables, and cheese sauce in equal proportion. Transfer to the prepared baking dish and spread into an even layer with a spatula. The casserole should fill the dish generously.
Sprinkle the remaining ½ cup provolone and ¼ cup mozzarella evenly over the top.
Bake uncovered at 375°F for 25 to 30 minutes, until the cheese topping is fully melted, bubbly, and beginning to turn golden at the edges. The center should be set — not liquid or jiggly when the pan is gently shaken.
For extra browning and a more caramelized cheese top: switch the oven to broil for 2 to 3 minutes after the bake time is complete. Watch carefully — cheese goes from perfectly golden to burned in under a minute under a broiler.
Remove from the oven and let rest for 10 minutes. This rest period allows the casserole to firm up and the internal temperature to equalize — cutting immediately produces servings that fall apart and lose their shape on the plate. After 10 minutes, the casserole slices cleanly and holds together beautifully.
Garnish with chopped fresh parsley. Serve with a green salad, steamed broccoli, or roasted vegetables.