Lulu's Mini Grilled Cheese Sandwiches

Who doesn't love these? Use truffle oil and fancy cheeses to make them gourmet.

1/2 lb. (2 sticks) salted butter, melted 20 slices potato bread (or other bread if you don't have potato bread) One 12-oz. package 4-cheese blend or grated Asiago, Parmesan, Fontina and Provolone 3 cups fresh baby spinach or arugula leaves Truffle oil or chili oil (optional)
Place a piece of wax paper on each of 2 baking sheets. Spread out 10 slices of bread on each baking sheet. Using a pastry brush, brush each slice with melted butter (Add a few drops of truffle oil or chili oil to the melted butter, if desired), turn bread over and brush other side.
Sprinkle two tablespoons cheese on each bread slice and cover with spinach or arugula. Place the other slice of bread on top and butter the top of the bread completely.
Cook the sandwiches in a large frying pan or on a griddle. Spray a frying pan with olive oil spray and bring to medium-high heat. Place sandwiches in the pan and let them brown for two to three minutes. Flip them over and cook for two to three minutes, or until brown. (I press a weight on the top of the sandwiches to get them crispy, but you can use a spatula to hold each one down.)
To serve, cut off the crusts, then cut each sandwich into 6 bite-size pieces. Serve warm.
Tip:You can make these ahead of time and store. After you cut off the crusts, place the pieces in a freezer bag, separating the layers with wax paper. To reheat frozen sandwiches, place them on a baking sheet and bake them in a 375 degree oven for 10 minutes. They will keep for up to one month in the freezer.