INGREDIENTS
1 lb
ground beef
1/4 tsp
salt
1/4 tsp
pepper
2 tsps
mustard
1 cup
onion
1 cup
mushroom
1/2 tbsp
worcestershire sauce
1 tbsp
red wine vinegar
1 clove
garlic
3 tbsps
butter
4
hamburger buns
4 slices
sharp cheddar cheese
1/4 cup
mayo
2 tbsps
mustard