Vegetarian French Onion Soup
This vegetarian French onion soup recipe calls for mushroom broth instead of beef stock, creating a surprisingly rich soup full of flavor — without the meat. This could become a staple recipe in vegetarian or meat-loving households! A long cooking time and savory ingredients mean this soup is pretty darn rich. Add in the toasted baguette slices and all that gooey Gruyère, and this soup is definitely the main course. Serve alongside a crisp, green salad.
salted butter
2
tablespoons
olive oil
2
tablespoons
red onions, thinly sliced
2
large
sweet onions, thinly sliced
2
large
kosher salt
2
teaspoons
white sugar
1
teaspoon
mushroom broth (such as Pacific Foods)
4
cups
fino dry sherry 
⅔
cup
vegan Worcestershire sauce (such as The Wizard's)
1
tablespoon
dried parsley
2
teaspoons
herbes de Provence
2
teaspoons
bay leaves
2
balsamic vinegar
1
tablespoon
Parmesan cheese rind
1
(1 ounce) piece
salt and ground black pepper to taste
French baguette slices
8
grated Gruyère cheese
¾
cup
grated Parmesan cheese
½
cup
 Melt butter with olive oil in a large pot over medium heat. Add red onions and sweet onions; sprinkle with kosher salt and sugar. Cook, stirring frequently, until onions are very tender and caramelized, about 45 minutes.
  Pour mushroom broth, sherry, Worcestershire sauce, parsley, herbes de Provence, and bay leaves into caramelized onion mixture. Bring to a simmer and cook over medium-low heat for 45 to 60 minutes.
  Reduce heat to low and remove bay leaves. Pour balsamic vinegar into soup and adjust seasoning. Mix well.
  Place Parmesan cheese rind in the center of the pot and submerge, but do not stir. Cook soup for 20 more minutes.
  Meanwhile, set an oven rack about 6 inches from the heat source and preheat the oven's broiler.
  Arrange baguette slices on a baking sheet.
  Toast baguette slices under the preheated broiler for 2 to 3 minutes per side. Remove from the oven and set aside.
  Carefully remove cheese rind from the pot and discard.
  Fill 4 oven-safe bowls evenly with soup and sprinkle each lightly with Gruyère and Parmesan. Top each with 2 baguette slices and sprinkle with remaining Gruyère and Parmesan. Place the soup bowls on a baking sheet.
  Broil soup in the preheated oven until cheese is browned and bubbling, 3 to 5 minutes.
