INGREDIENTS
1 1/2
lbs ground beef
1/2 cup
Panko bread crumbs
1
egg
1/4 tsp
black pepper
1 tbsp
all-purpose flour
1 1/2 cups
beef broth (low sodium)
1 oz
package brown gravy mix (dry)
2 tbsp
ketchup
1 tsp
dijon mustard
2 tbsp
butter
1
onion , thinly sliced
1 cup
mushrooms , thinly sliced
2 tbsp
cornstarch
4 tbsp
water
6
large rolls or Kaiser buns
6
slices swiss or cheddar cheese