Creating Oven Braised Beer Brats with Caramelized Onions is straightforward if you follow these steps:

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C).
2. Sauté Onions: In a large oven-safe skillet, heat the olive oil over medium heat. Add the sliced onions and cook until they become soft and translucent, about 10 minutes.
3. Add Garlic and Sugar: Stir in the minced garlic and brown sugar, cooking for an additional 5 minutes until the onions are caramelized and golden.
4. Add Bratwurst and Beer: Arrange the bratwurst sausages over the onions. Pour the beer over the bratwurst, and sprinkle salt, pepper, and mustard on top.
5. Braise: Cover the skillet with a lid or aluminum foil and transfer it to the preheated oven. Bake for 1 hour. For the last 10 minutes, remove the cover to allow for additional browning.

These simple steps will lead you to a delicious plate of Oven Braised Beer Brats with Caramelized Onions that will delight your taste buds.