Ingredients :
10 (approx) Sargento cheddar cheese slices
4 Tb Hellmann’s mayonnaise
1/2 tsp horseradish
1/2 pound thinly sliced roast beef
2 red onions; sliced
2 Tb Land O’ Lakes butter; divided
4 Sourdough bread slices
Instructions :
To Caramelize onions:
Add one tablespoon butter to a pan over medium heat. Caramelize the onions until soft, fragrant and beginning to char, about 10-15 minutes.
Once the onions are finished, turn off the heat and move them to one side of the pan. Add roast beef slices to the other side, just to warm them up a bit.
Liberally butter bread slices. Place one slice of bread buttered side down and add mayo and horseradish to taste, as well as two slices of cheese. Top with warmed roast beef, desired amount of caramelized red onion (about one-quarter cup) and another three slices of cheese. Place the other piece of bread on top (butter side up).
After about four minutes, check the bottom piece of bread by lifting the corner with a spatula. If browned to your liking, carefully flip and grill the other side, about four or five minutes. (You may want to cover the pan to help promote cheese melting.)