Lemon-Herb Vegetable Soup

This broth-based soup combines cabbage, chard, cauliflower, broccoli, zucchini, and aromatic vegetables in one bright, flexible pot. Adding the quicker-cooking green vegetables after the firmer vegetables preserves their color and texture, while lemon and fresh herbs sharpen the finished broth.

Yield: About 12 cups, or 6 servings
Prep time: 25 minutes
Cook time: 25 minutes
Total time: 50 minutes

Equipment

• 6-quart soup pot with lid
• Chef’s knife and cutting board
• Wooden spoon
• Liquid and dry measuring cups

Ingredients

• 1 tablespoon olive oil
• 1 medium yellow onion, diced
• 2 medium carrots, diced
• 1 celery rib, diced
• 1 red bell pepper, diced
• 2 garlic cloves, minced
• 2 teaspoons chopped fresh thyme, or 3/4 teaspoon dried thyme
• 6 cups reduced-sodium vegetable broth
• 2 cups shredded green cabbage
• 2 cups small cauliflower florets
• 2 medium zucchini, diced
• 2 cups small broccoli florets
• 2 cups chopped Swiss chard leaves, tough stems removed
• 1/2 teaspoon kosher salt, plus more as needed
• 1/4 teaspoon black pepper
• 2 tablespoons fresh lemon juice
• 2 tablespoons chopped fresh parsley
• 2 tablespoons chopped fresh chives

Method

1. Heat the oil in the soup pot over medium heat. Add the onion, carrots, celery, and bell pepper. Cook for 6 to 8 minutes, stirring occasionally, until the onion is translucent and the vegetables begin to soften.
2. Add the garlic and thyme. Stir for 30 seconds, just until fragrant; do not let the garlic brown.
3. Add the broth, cabbage, cauliflower, salt, and pepper. Increase the heat and bring to a boil. Reduce to a steady simmer, partially cover, and cook for 8 minutes.
4. Add the zucchini and broccoli. Simmer uncovered for 4 to 6 minutes, until the cauliflower is easily pierced with a fork and the broccoli is bright green. Add the chard and cook for 1 to 2 minutes, until wilted.
5. Remove the pot from the heat. Stir in the lemon juice, parsley, and chives. Taste only after adding the lemon, then adjust salt and pepper. Serve hot.

Ingredient Functions and Success Cues

The onion, carrot, and celery create a savory base. Cabbage gives the broth body, cauliflower and broccoli add bite, and zucchini softens quickly. Lemon balances the vegetables without long cooking, and the herbs contribute fresh aroma. The soup is ready when the firmest cauliflower piece is tender but intact.

Troubleshooting and Substitutions

If the broth tastes flat, add salt in small pinches before adding more lemon. If vegetables turn mushy, the simmer was too long or vigorous. Kale may replace chard but needs 3 to 4 minutes. Yellow squash may replace zucchini. Frozen broccoli can be added during the final 3 minutes without thawing. For a heartier soup, add one drained 15-ounce can of white beans with the zucchini.

Storage

Cool promptly and refrigerate in shallow covered containers for up to 4 days. Reheat to 165°F. Freeze for up to 3 months, leaving headspace in the container; thaw overnight in the refrigerator. The vegetables soften after freezing but remain suitable for soup.