Preheat oven to 325. Using a cuisinart, knives, a pastry cutter, or your hands grind 3/4 cup flour, powdered sugar, salt, anise, and butter until the butter has been broken down into small pieces. Press the mixture into a 8" tart pan. Bake until lightly toasted, 20-30 minutes.
Let crust cool. Mix eggs and sugar until well combined. Add juice and zest and mix well. Add flour. Pour into tart dish and bake until set, 30-40 minutes.