Fresh mushrooms contribute an earthy essence to the light broth for this soup. Gruyère is a rich, nutty-flavored Swiss cheese that's often melted atop French onion soup.
3 tablespoons olive oil, divided
2 medium onions, sliced
2 cups coarsely chopped mushrooms
1 cup dry white wine (we tested with Chardonnay)
3 (14 1/4-ounce) cans vegetable broth
3 sprigs fresh parsley
3 sprigs fresh thyme
1 bay leaf
1/2 teaspoon salt
3 medium onions, sliced
Butter or margarine
4 ounces Gruyère cheese, thinly sliced
1/4 teaspoon freshly ground pepper
How to Make It
Heat 2 tablespoons oil in a large skillet over medium-high heat until hot. Add 2 sliced onions and mushrooms; cook 5 minutes, stirring often. Reduce heat to medium; cook 15 minutes or until onion is browned. Add wine, and simmer 2 minutes. Add broth and next 4 ingredients. Bring to a boil; reduce heat, and simmer, partially covered, 30 minutes. Strain broth, discarding solids. Set broth aside.
Heat a large saucepan over medium heat until hot; add remaining 1 tablespoon oil. Add remaining 3 sliced onions, and sauté 10 minutes or until tender. Add reserved broth; cover, reduce heat, and simmer 25 minutes.
Toast baguette slices. Butter each slice and top with cheese; place on a baking sheet. Broil 3" from heat just until cheese melts.
Ladle soup into 6 serving bowls, and top with Gruyère toast. Sprinkle with pepper. Serve hot.