I typically use Johnsonville brats because I can get them locally year round.
I usually do one pack of five at a time because the wife doesn't like brats.
So 3 cans of cheap beer, 5 raw brats and one sliced up sweet onion is tossed in a pot and brought to a boil, boil uncovered for 20 minutes. Kill the heat, cover and let sit until cool. Scoop out the brats and onions, refrigerate for at least 12 hours.
Fire the grill, separate the brats and onions. Place the onions on a sheet of aluminum foil, add a heaping teaspoon of Webers Garlic and Sriracha spice, mix well and make the foil into a packet.
When grilling the brats, warm the onion packet on the grill.
When the brats are almost browned, toast your buns on the grill. Assemble the brats by putting the onions on the bread, generous portion of stone ground german mustard and the brat.
Enjoy. It's a nice mix of heat, sweet and sour.