Cheesy Sausages with Celery-Pickle Relish

Prepare a grill for medium-high heat; oil grate with vegetable oil. Remove any leaves from 3 celery stalks and set aside for serving. Cut stalks lengthwise into quarters, then thinly slice crosswise. Transfer to a medium bowl and add ¼ cup finely chopped pickles, 2 Tbsp. spicy brown mustard, 2 tsp. white wine vinegar, and 1 tsp. honey; mix well. Season relish with kosher salt and freshly ground pepper.

Working one at a time, slice down the length of 4 hot-dog-style bratwurst, hot dogs, or other cooked sausages, taking care not to cut all the way through. Open up bratwurst like a book and flatten.

Grill 4 hot dog buns, split, cut side down, to lightly toast, about 2 minutes. Transfer to plates. Grill bratwurst, cut side up, until lightly charred, about 2 minutes. Turn over and top with 4 oz. sharp white cheddar, thinly sliced, dividing evenly. Cover and cook until grill marks appear on cut side and cheese is melted, about 2 minutes.

Spread spicy brown mustard on inside of buns. Nestle bratwurst into buns so cheese creates a layer between buns and sausages. Fill split between sides of sausages with relish. Garnish with reserved celery leaves if using.