French Onion Soup with Barley

INGREDIENTS

6 cups

water

1 cup

hulled barley

2 tbsp

canola oil

1 1/2 lb

yellow onions, peeled and vertically sliced

1 lb

sweet onions, peeled and vertically sliced

3/4 tsp

kosher salt, divided

garlic cloves, thinly sliced

1/4 cup

dry sherry

6 cups

unsalted beef stock

1/2 tsp

freshly ground black pepper

thyme sprigs

bay leaf

1 1/2 tbsp

fresh thyme leaves

3 oz

French bread baguette, cut into 18 thin slices

3 oz

cave-aged Gruyère cheese, shredded (about 3/4 cup)

2 oz

part-skim mozzarella cheese, shredded (about 1/2 cup)