Beef Patties en Croute

1 pound lean ground beef
1/2 t salt
1 4-ounce can sliced mushrooms, drained
1/4 lb. liverwurst, cut into 5 slices
2 1/2 t prepared mustard
1 10-count package refrigerated biscuits

Shape ground beef into five 1-inch thick round patties; sprinkle with salt. In 10-inch skillet over high heat, cook patties 5 minutes or until browned on both sides, turning once. Drain on paper towels. Preheat oven to 450F. On lightly floured surface with floured rolling pin, roll one piece of biscuit dough into a 4-inch round. Place a liverwurst slice on center of dough round; top with a beef patty, 1/2 t mustard, and some mushrooms. Then roll another piece of biscuit dough into a 5-inch round; arrange on top of beef patty; press edges together to seal. If you like, cut a small piece of dough from edge of round to make a pretty design to use as a decoration. Repeat to make 5 in all. Place on cookie sheet. Bake 10 minutes or until crust is golden. 5 servings