Preheat your oven to 450°F. Set aside 4 ramekins or similar oven-safe dishes. Get all your ingredients ready.
Place a large nonstick skillet over medium-high heat. When hot, add the sausage and fry until browned, about 5 minutes. Use a wooden spoon to break up large clumps and stir the meat from the time to time.
Remove the cooked sausage to a plate. Next, add the onions, mushrooms and green peppers to the pan. Fry for several minutes until softened slightly.
Place the ramekins on a baking sheet. Brush the bottoms with pizza sauce. Add a layer of cheese. Then add a layer of cooked sausage and a layer of onion mixture.
Finish by brushing with more sauce and topping with more cheese. Then sprinkle parmesan and Italian seasoning. Add a few pepperoni slices on top of each pizza bowl.
Place the baking sheet with the pizza bowls into the preheated oven. Bake until the cheese is bubbling and golden, about 7 to 9 minutes.
Remove the ramekins from the oven. Let cool for 2 to 3 minutes before serving.