INGREDIENTS
4
thick slices applewood-smoked bacon, chopped into ½-inch pieces
1
large red onion, thinly sliced
Kosher salt and ground black pepper
1/3 cup
balsamic vinegar
1/2 tsp
Dijon mustard
1/3 cup
water
2
thick slices applewood-smoked bacon
1 1/2
lbs. ground beef (85% lean)
1/2 tsp
Worcestershire sauce
1 tsp
kosher salt
1/2
tsp. ground black pepper
Thinly sliced Gruyere cheese (optional)
4
hamburger buns
, split