Brush or spray Caramelized Onions & Beer Bratwurst with oil and grill over medium heat for 4-5 minutes, turning regularly, until heated throughout.
Add 2 tablespoons of the Dijon mustard to the top half of each toasted sub roll. Add ¼ cup of sauerkraut to the bottom. Top sauerkraut with a Bratwurst. Close sandwich; serve with an ice cold glass of Elysian beer.