Place 2 slices of bread on a cutting board and spread one teaspoon of mustard on one of the slices.  On the slice with the mustard, place two slices of cheese and top with marinated onions and pickles.

On the remaining slice, place two slices of cheese and top with 1/4 cup of coleslaw and 6 ounces of pastrami. Close the sandwich and set aside. Repeat to make a second sandwich.

In a large pan over medium heat, melt the butter and olive oil. When the butter has melted, place the sandwiches in the pan and turn the heat down to medium low; cook until the bread is crispy and golden, for 3 to 4 minutes.

Flip the sandwiches and allow the second side to brown and crisp, an additional 2 to 3 minutes. Then cover the pan with a lid for an additional minute, or until the cheese is melted, if necessary.

Cook’s Note: If you’re using homemade pastrami that has been refrigerated, take the chill off before making the sandwich by putting it in an oven-safe dish with a little bit of water. Cover the dish tightly with foil and warm it in a 350°F oven for bout 15 minutes.