- Servings: 4
1 single crust recipe of nice flaky pie dough or puff pastry
1 egg, beaten with a splash of milk or water (aka the egg wash)
1 1/2 tablespoons sour cream or creme fraiche (or, heck, even Greek yogurt)
1 1/2 tablespoons sugar (ideally coarse sugar), plus additional for sanding
~4 stalks rhubarb, thinly sliced on an angle
whipped cream for serving, if desired
Preheat the oven to 425° Fahrenheit. Line a baking sheet with parchment, or grease it well.
Let your dough come to room temperature. Roll out on a lightly floured countertop into a 12-inch by 16-inch rectangle. Trim off any ragged edges, and cut through the midpoints to divide into four smaller rectangles.
Brush the rectangles with the egg wash, right to the edges. Prick all over with a fork, leaving a 1/2-inch unpricked rim on the edges. Mix together the sour cream and sugar, then spread a thin layer on each rectangle, leaving the same 1/2-inch rim on the edges.
Lay down the rhubarb in overlapping slices (if you're so inspired, you could even spiral them in a floral formation, and if you are not feeling it at all you can just scatter them haphazardly). Fold the edges of the crust over, pressing down (especially at the corners) to seal. Brush the crust with another round of the egg wash, then generously sprinkle each tartlet (both crust and rhubarb) with a spoonful of the coarse sugar (I also like to sprinkle the crust part with a small amount of coarse salt too, if you have it, but that part's optional).
Transfer each tartlet to your prepared baking sheet, and bake until the crust is puffed and beginning to brown, ~20 minutes or so. Remove, let cool slightly, then serve with whipped cream.