Preheat the oven to 400°F.

In a large skillet, heat the olive oil over medium-high heat. Add the onion and sausage and cook for 3 minutes, breaking up the sausage with the back of a spoon.

Add the bell pepper and pepper flakes and cook for 2 minutes, or until the sausage is cooked through. Remove the skillet from the heat.

In a medium bowl, beat the eggs. Add the cream and sea salt and black pepper to taste. Mix well. Pour the egg mixture into the skillet and stir to combine.

Transfer the mixture to an ovenproof rectangular baking dish. Top with the mozzarella and pepperoni. Bake for 15 minutes. Serve warm.