Mix together the melted butter and flour, forming a dough.
Stir in the chopped pecans.
Press the crust into an un-greased 9x13 baking dish.
Bake at 350° F for about 20 minutes, or until the crust begins to turn a golden brown.
Let the crust cool before adding any filling.
Notes
If you are making this crust with a recipe where you bake the crust with the filling, just bake it according to the instructions for that particular recipe.