These summery tarts are bursting with berries and crème fraîche. Allow guests to fill their own tarts at the table, so that the shells don't become soggy.
Place the flour, 1 1/2 tablespoons sugar, and salt in a food processor. Pulse to combine. Add butter, and process until mixture resembles coarse meal.
In a small bowl, mix together egg yolk and ice water. With machine running, add egg mixture in a slow, steady stream through the feed tube. Process until dough just holds together, about 20 seconds. If dough feels dry, add more ice water, 1 tablespoon at a time.
Preheat oven to 400 degrees. Divide the dough evenly among six 4-inch tartlet pans; gently press into pans. Prick bottoms with a fork. Refrigerate shells until firm to the touch, at least 30 minutes.
Line each shell with foil, and fill with pie weights or dried beans. Place tart pans on a rimmed baking sheet; bake until the edges just begin to brown, about 15 minutes. Remove foil and weights. Continue to bake until bottom of crust is golden brown and crisp, about 10 minutes more. Transfer to a wire rack; let cool completely. Remove shells from pans.
Meanwhile, in a medium bowl, mix strawberries with remaining 3 tablespoons sugar. Cover with plastic wrap, and let macerate until juicy, about 1 hour.
When ready to serve, fill each tart shell with about 1/3 cup creme fraiche; divide strawberries evenly among tarts.
This dough can be frozen for up to one month; thaw before using.