Preheat oven to 350*
Spread mustard evenly along the bottom of the pie crust with the back of a spoon.
Spread olive oil over the mustard. Sprinkle or layer on the cheese on the crust. Top with layer of tomatoes, placing the first slice in the center and moving out slightly overlapping circles until crust is covered. ( only one layer of tomatoes )
Salt and pepper.
Bake for 30 minutes or until crust is golden and cheese bubbles.