Swiss Mushroom Turkey Melts

Melt butter in a medium skillet over medium-high heat. Add sliced onion and cook, stirring occasionally, for 4-5 minutes or until onion is soft and turns translucent. Add mushrooms to skillet and continue cooking for 5 minutes or so until the mixture is completely cooked through and the vegetables begin to brown slightly. Stir in Worcestershire and a pinch of salt and pepper, to taste. Cook another 2-3 minutes. Remove from heat and set aside. Tip: this can be done a day or two ahead.

Preheat oven to 400ºF. Toast bread either in the toaster or on a sheet pan in the oven. Smear mustard on one side of each slice. Place slices, mustard-side up, on the baking sheet. Top each slice with 2 slices of turkey, 1/4 of the mushroom-onion mixture, and a slice of cheese. Bake in the oven for 5-8 minutes or until filling is heated through and cheese is completely melted.