Caramelized Onion and Cheese Quiche

Preheat your oven to 350 degrees Fahrenheit, or 175 degrees Celsius.

Next, take a moment to prepare your baking dish by coating it with a thin layer of grease. This will prevent any food residue from sticking to the dish during cooking.

In a large skillet, heat together butter and olive oil over medium-high heat. Add sliced onion to the pan and stir occasionally until it becomes tender, approximately 10 minutes later. Remove the cooked onion from the skillet and set it aside to cool.

In a separate bowl, combine heavy cream, eggs, salt, and black pepper. Stir until well combined, then add shredded mozzarella cheese, grated Parmesan cheese, and the cooled onion. Mix everything together until you have a smooth, creamy batter.

Pour this mixture into your prepared baking dish and place it in the preheated oven. Allow the eggs to cook until they are fully set, and when you insert a knife into the center of the dish, it should come out clean. The edges of the dish should be lightly browned, but the top surface should still appear pale and uncooked.