Vegetarian French Onion Soup

Katie Choi, Photo by Anastassios Mentis

Vegetarian French Onion Soup
cover of the KIWI Fall 2022 issue


Makes 8 servings

3 large yellow onions, thinly sliced pole-to-pole (5 to 6 cups)

2 Tablespoons olive oil

1 teaspoon sugar

1 Tablespoon flour

1 teaspoon fresh thyme leaves

4 cups low-sodium vegetable broth

1 Tablespoon low-sodium soy sauce

1 teaspoon balsamic vinegar

1⁄2 teaspoon kosher salt

1⁄4 teaspoon pepper

1 whole wheat baguette, cut into 1⁄2-inch slices

8 ounces shredded Gruyère, Fontina, or mozzarella cheese

This hearty appetizer captures all the irresistible flavor of the traditional dish—without the beef broth. You can even pair it with a salad for a light supper.


1. Grease the inside of a slow cooker crock with cooking spray or olive oil. Add sliced onions, olive oil, and sugar to the crock; toss to coat. Cover and cook on high for 4 hours, stirring once halfway through.

2. Add flour and thyme to onion mixture; cook, stirring, for 1 minute. Add vegetable broth, soy sauce, vinegar, salt, and pepper. Cover and cook on low for 4 hours. Taste for seasoning.

3. Before serving, preheat broiler. Divide soup into oven-safe crocks and top each with a baguette slice and a handful of shredded cheese. Broil for 1 minute, until the cheese is melted and bubbly. (Alternatively, arrange baguette slices on a broiler pan, top with cheese, and broil until cheese melts. Serve soup with cheesy croutons.)

Per Serving:

Calories: 223

Carbohydrates: 10 g

Fat: 16 g

Protein: 10 g

Fiber: 2 g

Active Time:

20 minutes

Total Time:

8 hours 20 minutes