Ingredients
¼ cup extra-virgin olive oil
2 small onions, chopped
3 garlic cloves, minced
3 carrots, peeled and cut crosswise into ¼-inch rounds
2 celery stalks, cut crosswise into ¼-inch pieces
1 bunch Swiss chard, leaves torn into small pieces, stems cut crosswise into ½-inch pieces
8 ounces green beans, trimmed and cut into 1-inch pieces
4 medium ripe tomatoes, peeled and diced
Coarse salt and ground pepper
2 medium zucchini or yellow squash, cut into a ½-inch dice
1 parmesan rind or ¼ cup finely grated parmesan, plus more, grated for serving
1 can (15 ounces) butter beans, cannellini beans, or chickpeas, drained and rinsed
Fresh basil leaves, torn if large, for serving (optional
Instructions
Heat the oil in a large pot over medium heat. Add onions and garlic; cook, stirring occasionally, until onions are translucent, about 5 minutes. Add carrots, celery, and chard stems; cook, stirring occasionally, until chard stems are translucent, about 10 minutes. Add green beans and tomatoes. Season with 2 teaspoons salt; cook, stirring occasionally, until beans and tomatoes start to soften, 5 minutes.
Add zucchini, 5 cups water, parmesan rind, and butter beans. Bring to a boil, then reduce to a simmer. Cook until all vegetables are softened, about 25 minutes, adding chard leaves in last 2 minutes of cooking. Season with salt and pepper. Serve immediately, topped with grated parmesan cheese and basil, or freeze up to 3 months.