Chocolate Gravy

In a bowl mix:

1/2 cup flour, 1/4 cup cocoa, 3/4 cup sugar

Add 3/4 cup evaporated milk  and mix well.  (I use 1/4 cup  evaporated milk, then add enough water to make 3/4 cup)  Bring to boil 3 cups water.  Add above mixture to boiling water, stirring as you add mix.  When thick add 1 tsp vanilla and 2 tbsp. butter.  Serve with hot biscuits.