Preheat the oven to 200 °C for the casserole with tortellini and bacon. Peel the onion, clean the bell pepper and remove the core, cut both into small pieces.
Cut the bacon into thin strips. Cut cheese into small cubes. Steam tortellini for 15 minutes. Fry bacon in a pan, add onion and roast until golden.
Coat a square baking dish with olive oil, fill in tortellini, spread onion mixture, diced peppers and cheese cubes on top.
Season whipped cream, sour cream and egg with salt and pepper, whisk and pour over tortellini. Cut the mozzarella into small pieces and spread over the casserole. Put the casserole in the preheated oven and bake for about 35 minutes.
Arrange the casserole with tortellini and bacon and serve.