Tomato Tart from The Best Recipes in the World: More Than 1,000 International Dishes to Cook at Home by Mark Bittman

Ingredients

• Salt and black pepper to taste
• 8 tablespoons (1 stick) butter at room temperature
• 4 large tomatoes
• 4 to 5 tablespoons Dijon mustard as needed
• Extra virgin olive oil as needed
• 1 tablespoon fresh thyme leaves
• 2 cups flour, plus more for rolling the dough
• 1 egg