Servings: makes 4 servings
Prep Time: 10 minutes
Cook Time: 50 minutes
Total Time: 1 hour
- 1 tablespoon olive oil
- 4 cups onion, sliced
- 1/2 cup water
- 4 buns, cut in half and lightly toasted
- 4 slices cheese, cheddar, swiss or provolone
- 1 pound roast beef, warm and thinly sliced
- 1/4 cup gravy
- 2 tablespoons mayonnaise
- 1 tablespoon horseradish
- 1 tablespoon grainy mustard
- 1 handful arugula (optional)
- Heat the oil in a pan over medium heat.
- Add the onions and water and cook, covered, until completely tender and caramelized and golden, about 40-50 minutes, adding more water as needed.
- Mis the mayo, horseradish and mustard.
- Assemble sandwiches and enjoy!