Cream butter and cheese, beating until smooth. Combine flour and salt and add half at a time to cheese mixture. Mix thoroughly.
Shape in ball, wrap in waxed paper and chill until pastry will roll and handle easily. (Or shape in 2" rolls, wrap, refrigerate overnight and slice in about 18 circles.) Roll, cut in 2" circles and bake in (2") muffin-cup pans in very hot oven (450°F.) about 12 minutes, or until lightly browned. Cool before filling.