Minneapolis Dog: Cheddar-Filled Hot Dog with Grilled Onions and Mustard
Heat the olive oil in a skillet over medium-high heat. Add onions and cook, stirring occasionally, until onions are golden-brown and softened, 8–10 minutes. Set aside.
Cut a long slit lengthwise in each hot dog (do not cut all the way to the ends); tuck 1 piece of cheese snugly into each hot dog. Grill hot dogs, cheese-side up, until cheese is melted. Arrange hot dogs in toasted buns and top with the grilled onions and a drizzle of mustard.