Photo by Zachary Cross

Spring is here and warm weather is coming, too. When you need a warm soup for one of the chilly evenings we have left try a vegetarian version of the classic French onion soup.

This week’s post comes courtesy of my husband, Jeffrey, who has perfected the recipe from making countless pots. I’ll let him explain:

I’ve made this soup for years. I’ve always called it “French Onion Soup” and only realized when reviewing the recipe for this post that the Moosewood recipe is simply called “Onion Soup”. Well, I’m going to keep calling it “French” for what it’s worth! I made this for quite a while pretty much according to the Moosewood recipe, with the main adjustments being that (1) more butter is better (we have the 15th anniversary cookbook from the low-fat 90s); and (2) we like more mustard and no white pepper. Besides the fact that I would never make it without making at least a double if not triple recipe – this soup only gets better with age!

The only thing about making a vegetarian French Onion Soup is that the quintessential ingredient in a traditional recipe is beef broth. I liked this soup very much, making it according to the recipe, but was it lacking something that could give it more depth? At some point in the past couple of decades I came up with an answer: miso! Miso is a “paste made from fermented soybeans and barley or rice malt”. Maybe you’ve had a bowl of traditional miso soup at a sushi restaurant. There are several kinds of miso available in your local Whole Foods or maybe other stores. They may be hiding near the tofu, tempeh and veggie kielbasas in a forgotten corner of the produce department..!? For this recipe I have used both chickpea miso and traditional red miso. I think chickpea miso is my personal favorite, but perhaps the red miso, with its darker complexion, is the richer, more appropriate choice to replace the beef broth in onion soup.

Adding miso to this onion soup is very simple, but it gives the soup a significant flavor kick. The most important thing to note is that you do not want to boil the miso. Whereas the recipe calls for four cups of water, instead add just three cups of the water (or the correct proportional amount if you are making a larger recipe). Reserve the last cup of water in a bowl or liquid measure. Heat the water to boiling if it is not already. Then add 2-3 Tablespoons of miso paste. Stir it well with a spoon, pressing the paste against the side of the bowl to break it up. Add the miso mixture when the rest of the soup is done simmering, and turn the heat down to warm or off. Stir well and then let the soup rest for a few minutes before serving.

As for serving this soup with croutons… well that sounds great but making the homemade croutons seems like maybe more trouble than it’s worth. Instead I like to make a batch of cheese toast in the toaster oven while the soup is resting. The diners can choose whether to serve soup over the cheese toast in bowls, dip the toast in the soup, or enjoy them separately. It’s good no matter what!

Onion Soup
From The Moosewood Cookbook by Mollie Katzen
Preparation time: 1 hour (mostly for simmering)    Yield: 6 servings

2 Tbs butter
4 large yellow onions, thinly sliced
1 tsp salt
½ tsp dried mustard
A dash or two of thyme
4 cups water
2 Tbs soy sauce
2 to 3 Tbs dry white wine (optional)
A few dashes of white pepper

Toppings:
Thin slices of Swiss cheese
Croutons

Melt butter in a kettle or Dutch oven. Add onions and salt, and cook over medium heat about 10 minutes, stirring occasionally.

Add mustard and thyme; stir and cover. Continue to cook very slowly for about 35 more minutes. The onions will be exquisitely soft and simmering in their own liquid.

Add water, soy sauce, optional wine, and white pepper. Simmer at least 10 minutes more. Taste to adjust seasonings. Serve topped with croutons and Swiss cheese. If you’re serving the soup in ovenproof bowls, you can put them under the broiler briefly, to brown the cheese. Be careful handling the bowls!