1 (15 ounce) package folded refrigerated pie crust
1 cup (4 ounce) shredded pepper-jack cheese
1 cup (4 ounce) shredded Swiss cheese
1 1/2 cups (8 ounces) finely chopped leftover roast beef
1 cup (1/2 pint) heavy cream
1/4 teaspoon dry mustard
1/4 teaspoon black pepper
Preheat oven to 325 degrees F. Unfold the pie crust and place in a 9-inch deep-dish pie plate, pressing the crust firmly into the plate.
In a medium bowl, combine the pepper-jack cheese, Swiss cheese and roast beef; mix well and spoon into the pie crust.
Using the same bowl, whisk together the remaining ingredients; pour over the roast beef and cheese mixture. Bake for 55 to 60 minutes, or until a knife inserted in the center comes out clean.
Cut into 8 pie-shaped wedges to serve.