In a food processor, combine the flour, sugar, salt, and half of the butter. Pulse 4-5 times until loosely combined, then add the rest of the butter and pulse an additional 5-6 times until just starting to look sandy.
Drizzle half of the cold water over the flour mixture, and pulse to combine. Add a little more water at a time just until the dough sticks together when pressed.
Form the dough into a ball, wrap in plastic wrap, then flatten into a disk and refrigerate, at least 30 min.
Thyme Bechamel
Melt the butter in a saucepan over medium heat. Whisk the flour into the melted butter until combined.
Cook the flour and butter mixture, stirring constantly, until bubbling and beginning to turn golden, about 2 minutes.
Whisk the milk and thyme into the flour and butter. Simmer, whisking constantly, until the sauce becomes very thick, about 7 minutes. Whisk in the salt, nutmeg and parmesan.
Tomato Filling
Preheat your oven to 375°F.
Roughly chop the roma and cherry/grape tomatoes.
On a large sheet pan, mix the chopped tomatoes with the garlic and olive oil, and lightly season with kosher salt and black pepper.
Roast the tomatoes for 1 hour at 375°F, then lower the oven to 275°F and roast 1 additional hour, until caramelized.
Tomato Pie with Thyme Bechamel
Preheat your oven to 350°F or turn on your mini-pie maker.
Roll out the pie crust to ⅙th of an inch in thickness. If making mini-pies, cut out circles of crust that fit the size of your pans or mini-pie maker.If making full size pies, cut out the crust into circles about 11 inches in diameter.Press the crust into the pie pans, or pie-maker. Prick all over with a fork to prevent bubbling.
If using an oven:Pre-bake your crust for 12 minutes, until just beginning to brown. Then, add a generous layer of the thyme bechamel to the bottom of the crust. Top the bechamel with a layer of roasted tomatoes.Bake the pies (30 minutes for a full size pie, 15 minutes for mini pies).
If using a mini-pie maker:Press the crust into the molds of the mini-pie maker. Then, add a generous layer of the thyme bechamel to the bottom of the crust. Top the bechamel with a layer of roasted tomatoes.Close the lid of the pie maker and cook for 5 minutes, until the edges of the crust begin to brown. Continue cooking the pies with the lid open, an additional 5-8 minutes, until the crust is golden brown on the bottom.