2. In a large pot, add the brats, beer, and sliced onion. Bring to a boil, then reduce heat and simmer for 10-15 minutes.
3. Remove the brats from the pot and place them on the preheated grill. Grill for 10-15 minutes, turning occasionally, until they are browned and cooked through.
4. Serve the brats on hot dog buns with your favorite toppings.