1 tablespoon olive oil
2 cups chopped onions
1 tablespoon chopped fresh rosemary (1 teaspoon dried)
1 cup diced celery
1 cup peeled and chopped carrots
1 teaspoon salt
3 cups undrained chopped canned tomatoes (28-ounce can)
3 1/2 cups water
4 cups rinsed and chopped kale
1/4 to 1/3 cup fine cornmeal (use more or less for a thicker or thinner soup)
salt and ground black pepper to taste
Warm the olive oil in a nonreactive soup pot. Add the onions and rosemary and sauté on medium-high heat for five minutes, stirring frequently. Add the celery, carrots and salt and continue to sauté for five minutes. Add the tomatoes and three cups of the water, cover and bring to a boil; then lower the heat to a simmer and cook for 10 minutes.
Add the kale and simmer for about 10 minutes longer, until all of the vegetables are tender. In a bowl, whisk together the cornmeal and the remaining 1/2 cups of water until smooth and lump-free. Add it to the soup in a slow stream while stirring briskly. Simmer for five minutes. Add salt and pepper to taste, and optionally serve with grated Parmesan or Pecorino Romano cheese.