- 3 tablespoons olive oil
- 4 Italian sausages
- 3 red bell peppers, thinly sliced
- 1 yellow onion, thinly sliced
- 1/2 teaspoon kosher salt
- 1/4 teaspoon black pepper
- 4 hard rolls, halved and (if desired) toasted
- 4 tablespoons Dijon mustard
- Heat 1 tablespoon oil in a skillet over medium heat. Add the sausages and cook, turning, until browned on all sides and cooked through, about 15 minutes.
- Meanwhile, heat the remaining oil in another skillet over medium heat. Add the peppers, onion, salt, and pepper. Cook until soft and golden, 10 to 12 minutes.
- Toast rolls if desired. Halve the sausages lengthwise. Place 2 halves on the bottom of each roll and top with the pepper-onion mixture.
- Cover with another roll half, if desired. Serve the mustard on the side.