In bowl, toss together strawberries, rhubarb, orange juice, orange zest, liqueur, and sugar; set aside. Preheat convection oven to 375 degrees, or conventional oven to 350 degrees. Coat 50 2-inch fluted tartlet pans with cooking spray; line bottoms with 1 1/2-inch parchment rounds.Advertisement
On lightly floured surface, roll out dough 1/8 inch thick. Cut with 2 1/2-inch cutter; press into pans. Reserve rolled scraps for lattice. Cut into 1/4-inch strips, and chill pans and scraps until very cold.
Strain fruit mixture; place 1 1/2 tablespoons in each tartlet shell. For each, dip six dough strips in egg wash; make lattice over filling. Trim away excess dough.
Transfer tartlets to parchment-lined baking sheets. Bake until golden brown, about 40 minutes, rotating after 20 minutes. Use wooden skewer to gently loosen edges of tartlets and remove from pans while still hot; if you wait until they cool, the fruit overflow will make them stick.