Ingredients
2 tablespoons extra-virgin olive oil
2 large sweet onions, such as Vidalia, halved and thinly sliced (4 cups)
Kosher salt
2 teaspoons caraway seeds
1 dried bay leaf
2 tablespoons spicy brown mustard, plus more for serving
3 tablespoons packed light-brown sugar
6 precooked bratwursts
2 bottles (each 12 ounces) lager beer
2 cups sauerkraut, strained
6 hoagie rolls, split
Preparation
Heat 1 tablespoon oil in a large, grill-safe straight-sided skillet (preferably cast iron) over medium. Add onions and a pinch of salt. Cook, stirring occasionally, until onions are soft and golden in places, about 20 minutes. Stir in caraway seeds, bay leaf, mustard, and brown sugar; cook 30 seconds. Add bratwursts and beer. Bring to a boil, then reduce heat to medium-low and simmer, turning bratwursts occasionally, 20 minutes.
Preheat grill for direct-heat cooking (medium-high on a gas grill). Transfer bratwursts to a plate. Drain onion mixture in a fine-mesh sieve; discard liquid. Return mixture to skillet with remaining 1 tablespoon oil. Place on one side of grill and cook, stirring occasionally, until golden brown, about 5 minutes. Stir in sauerkraut; cook 1 minute more.
Meanwhile, place bratwursts on grill and cook, turning a few times, until blistered in places, about 5 minutes. Place rolls on grill, cut-sides down, until lightly toasted and charred in places, about 1 minute.
Serve bratwursts in rolls, topped with sauerkraut mixture and more mustard.
