INGREDIENTS
6 tbsp
butter
4
large yellow onions, sliced and separated into rings
1 tbsp
white sugar
2 cloves
garlic, minced
1/2 cup
cooking sherry
7 cups
reduced-sodium beef broth
1 tsp
sea salt, or to taste
1/4 tsp
dried thyme
1
bay leaf
8
slices of French bread
1/2 cup
shredded Gruyere cheese
1/3 cup
shredded Emmental cheese
1/4 cup
freshly shredded Parmesan cheese
2 tbsp
shredded mozzarella cheese