- In a large bowl, whisk together the flour, salt, and thyme leaves. Add the cold butter cubes and blend them in—using a pastry knife, a pair of butter knives, or your fingers—until the largest pieces of butter are the size of peanuts. In a measuring cup or small bowl, whisk together Greek yogurt, lemon juice, and cold water, then pour into the bowl with the flour mixture. Stir just until the dough comes together—it will still look dry and shaggy—and gather it together with your hands until it forms a ball. Wrap the ball tightly in plastic, then press it lightly into a thick disc shape. Refrigerate the dough for at least 30 to 60 minutes, or up to overnight.
- Preheat the oven to 400°F/204°C, and line a baking sheet with parchment paper, aluminum foil, or a silicone baking mat.
- Unwrap the disc of dough and place it on a floured countertop. Roll the dough out to a rough 12-inch circle. Transfer the circle of dough to the prepared baking sheet: lightly fold the dough in half, then in half again to make a triangle shape. Place the dough on the baking sheet, and gently unfold it back into a circle in the middle of the pan.
- Mix the two types of grated cheese together in a small bowl. Sprinkle the cheese mixture evenly over the middle of the crust, leaving a 2-inch border around the edges, and reserving a few pinches of cheese for the egg wash later. Lay the tomato slices in a single layer over the cheese, overlapping if necessary. Arrange the onion slices on top of the tomatoes, followed by the asparagus. Sprinkle the salt and pepper evenly over the vegetables, then top with the cubed mango and a pinch of red pepper flakes. Fold the border of the crust up and over the vegetables, pleating as you work around the edge, forming a circular pie with a large open area in the center.
- In a small bowl or cup, whisk together the egg yolk and water until blended. Brush the crust evenly with the egg mixture, then sprinkle over the reserved cheese. Place on the center oven rack and bake until the crust is golden brown, 30 to 40 minutes. Let rest for 5 to 10 minutes, then serve hot and enjoy!
Recipe submitted by Adam Merrin and Ryan Alvarez, Husbands That Cook