2 tablespoons olive oil, plus more for serving (optional)
1 medium red onion, chopped
2 medium carrots, peeled and diced
1 large celery stalk, diced
1/4 teaspoon red-pepper flakes
1 teaspoon minced fresh rosemary, or 1/4 teaspoon dried
Coarse salt and ground pepper
1 can (14.5 ounces) whole peeled tomatoes, drained and finely chopped
1 large potato, peeled and diced
1/4 head Savoy or green cabbage (1/2 pound), cored and thinly sliced
1 can (15 ounces) cannellini beans, rinsed and drained
1/2 pound green beans, trimmed and cut into 1-inch pieces
1 garlic clove, minced (optional)
1/4 cup thinly sliced fresh basil, plus torn leaves for serving (optional)
3/4 cup grated Parmesan, for serving
In a large pot, heat oil over medium. Add onion, carrots, celery, red-pepper flakes, rosemary, 1 1/2 teaspoons salt, and 1/4 teaspoon pepper. Cook, stirring occasionally, until onion begins to turn golden, 5 to 8 minutes.
Add tomatoes; cook until some of the liquid evaporates, 1 minute. Add potato, cabbage, cannellini beans, and 7 cups water; bring to a boil. Stir in green beans.
Reduce to a simmer, and cook until all the vegetables are tender, about 20 minutes. Season with salt and pepper; stir in garlic, if using, and basil. Serve sprinkled with Parmesan and, if using, torn basil. Drizzle with more oil, if desired.
For variations on this classic version, try swapping zucchini for green beans, kale for cabbage, and chickpeas for cannellini beans.
Prep: 30 minutes
Total: 1 hour