Bok Choy and Shiitake Soup

Ingredients

• 5 large leeks, trimmed, halved, rinsed, and cut into chunks
• 5 yellow onions, quartered
• 8 carrots, coarsely chopped
• 6 celery stalks, coarsely chopped
• 6 sprigs fresh flat-leaf parsley
• 1/2 pound button mushrooms, halved
• 10 whole black peppercorns
• 5 quarts water
• Kosher salt, to taste
• 4 cups prepared vegetable stock
• 1 head bok choy, halved lengthwise and thinly sliced
• 1/2 pound shiitake mushrooms, stems removed and caps thinly sliced
• 4 green onions, including green tops, sliced
• 1/4 pound snow peas, thinly sliced
• 2 teaspoons soy sauce
• 1/4 teaspoon toasted sesame oil
• Freshly ground black pepper, to taste

Instructions

1. Combine the leeks, onions, carrots, celery, parsley, button mushrooms, peppercorns, and water in a large stockpot. Bring to a boil over high heat.
2. Reduce the heat to medium-low, partially cover, and simmer for about 1 hour, until the vegetables are very soft and the stock is flavorful.
3. Season the stock lightly with salt. Strain it through a fine-mesh sieve into a large bowl, pressing gently on the vegetables, then discard the solids. Reserve 4 cups for the soup and refrigerate or freeze the remainder.
4. Bring the reserved 4 cups of vegetable stock to a gentle simmer in a large saucepan over medium-high heat.
5. Add the bok choy, shiitake mushrooms, green onions, snow peas, soy sauce, and sesame oil. Reduce the heat to medium-low and simmer uncovered for about 10 minutes, until the vegetables are tender but still colorful.
6. Taste and adjust with salt and black pepper. Ladle into four bowls and serve hot.