1 large onion, chopped
2 carrots, sliced
2 celery stalks, chopped
2 garlic cloves, minced
1 medium zucchini, chopped
1 1/2 teaspoons ground fennel seeds
2 teaspoons ground oregano
1/2 teaspoon ground black pepper
1/8 teaspoon red pepper flakes or to taste
3 cups chopped tomatoes (see note)
1 1/2 cups cooked cannellini beans or 1 (15 ounce) can low sodium cannellini beans, drained
5 cups kale or other greens, tough stems removed, and chopped
8 ounces bean pasta