Preheat and prep: Heat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with a little oil or butter.

Sauté aromatics: Warm 1 tablespoon of oil in a large skillet over medium heat. Add the diced onion and cook 3–4 minutes until softened. Stir in minced garlic and cook 30 seconds, just until fragrant.

Brown the beef: Add the ground beef and break it up with a spatula. Season with salt, pepper, and Italian seasoning. Cook until browned and no longer pink, about 6–8 minutes. If there’s a lot of grease, drain excess fat, leaving a couple of tablespoons for flavor.

Add tomato paste: Stir in the tomato paste and cook 1–2 minutes to caramelize it slightly. This deepens the flavor without adding carbs.

Create a creamy base: Lower the heat and pour in the heavy cream. Stir until smooth and lightly thickened, 1–2 minutes. Taste and adjust salt and pepper. Add a pinch of red pepper flakes if you like a little heat.

Layer in the dish: Spread the beef mixture evenly in the baking dish. Dollop the pesto over the top and lightly swirl it into the meat with a spoon. Don’t fully mix; you want ribbons of pesto throughout.

Add the cheese: Sprinkle shredded mozzarella evenly over the top. Add slices of fresh mozzarella here and there for extra melt and texture. Finish with grated Parmesan.

Bake: Place the dish on the center rack and bake 15–18 minutes, until the cheese is melted and bubbling.

Broil for color (optional): Switch to broil for 1–2 minutes to get golden, blistered spots on the cheese. Watch closely to avoid burning.

Rest and garnish: Let it rest 5 minutes to set. Garnish with torn fresh basil. Slice and serve warm.