2 lb. medium onions, halved lengthwise, then sliced lengthwise
3 sprigs fresh thyme
2 bay leaves
¾ tsp. salt
¼ cup grapeseed oil
2 tsp. flour
¾ cup dry white wine
4 cups (32 fl. oz.) reduced-sodium beef broth
1½ cups water
½ tsp. black pepper
2-3 chicken bouillon cubes
6 (1/2-inch-thick) diagonal slices of baguette
Shredded gruyere cheese, for topping
Instructions
Preheat oven to 350 degrees.
Cook onions, thyme, bay leaves, and salt in grapeseed oil in a 4- to 5-quart heavy pot over moderate heat, uncovered, stirring frequently, until onions are very soft and deep golden brown, about 45-50 minutes. Add flour and cook, stirring, 1 minute. Stir in wine and cook, stirring, 2 minutes. Stir in broth, water, bouillon cubes, and pepper and simmer, uncovered, stirring occasionally, 30 minutes. Season with salt and pepper.
Brush bread pieces with olive oil and season with salt and pepper. Arrange bread in 1 layer on a large baking sheet and toast, turning over once, until completely dry, about 15 minutes.
Remove croûtes from oven and preheat broiler. Put crocks in a shallow baking pan.
Discard bay leaves and thyme from soup and divide soup among crocks, then float a croûte in each. Top with desired amount of shredded gruyere.
Broil until cheese is melted and bubbly, and slightly browned, 5-7 minutes.