Grilled Hamburger with Caramelized Onions and Grilled Pineapple

INGREDIENTS

1 tbsp

olive oil

onions (, medium or large, sliced)

salt

1 tbsp

balsamic vinegar

1 lb

ground beef (80% lean)

salt and pepper

2 tbsp

vegetable oil

slices cheddar cheese

slices pineapple (or pineapple rings )

1 tbsp

olive oil

2 tbsp

honey

hamburger buns (, toasted and warmed)

1 cup

lettuce

tomatoes (, sliced)

1/2

red onion (, sliced)