In a medium pot over medium heat, combine sauerkraut, beer, Mountain Dew and butter. Bring to a boil, then reduce to a simmer until beer reduces by half and butter is melted, stirring regularly, about 10 minutes. Add brats and heat until cooked through.
Remove brats from braise and place on the grill, turning every few minutes, until cooked through, about 10 minutes.
Drizzle onion rings with olive oil to coat. Grill onions, flipping once, until softened and grill marks appear, about 4 minutes. Remove from grill and set aside.
To assemble, apply spicy brown mustard to the bread. Place brat inside the roll and top with sauerkraut, grilled onions, and Lay’s Kettle Cooked Jalapeño Potato Chips and serve.