This recipe is not fast but surprisingly, it's little hassle. It's also extremely delicious.
3 tablespoons butter or margarine
6 medium onions, thinly sliced
1/4 teaspoon salt
4 cups water
1 can (14 1/2 ounces | 1 3/4 cups) chicken or vegetable broth
1 teaspoon dried thyme
4 slices (1/2 inch thick) french bread - I used french sour dough
4 ounces (1 cup) Gruyère, swiss or muenster cheese
In a large pot melt butter over medium heat.
Add onions and salt.
Cook, stirring occasionally, until onions are very tender and begin to caramelise - about 45 minutes.
Reduce heat to low; cook, stirring often, until onions are deep golden brown, about 15 minutes longer.
Put onions in a bowl.
Add 1/2 cup of water to pot; heat to boiling over high heat, stirring until browned bits are loosened from bottom.
Add broth, thyme, and remaining water.
Heat to boiling over high heat.
Reduce heat to low; cover and simmer about 30 minutes, until onions are very tender.
Meanwhile pre-heat over to 450'f.
Place four 2 1/2 cup oven safe bowls in jelly-roll pan.
Spoon onion soup in bowls; top with bread pressed lightly into soup.
Put cheese on bread.
Bake until cheese melts and begins to brown, 12 - 15 minutes.
*I use larger oven proof bowls than the 2 1/2 cup ones. Mine are big enough to top with 2 slices of bread.