Umbrian Vegetable Soup

This recipe is from Lidia Bastianich in Saveur magazine. I love a good soup on a cold winter's day, and this soup does not disappoint. The soffritto is the key to developing the flavor, but adding some Parmesan rind really helps provide depth. A soffritto is a vegetable mixture used in several Mediterranean cuisines as a base for soups and sauces. I don't really like frisée all that much so feel-free to substitute. I like escarole or broccolini.

1⁄2 cup packed basil leaves
1⁄4 cup extra-virgin olive oil, plus more for drizzling
2 tbsp. minced fresh flat-leaf parsley
4 cloves garlic
1⁄2 medium onion, cut into chunks
8 oz. red new potatoes, cut into 1⁄2" cubes
3 stalks celery, minced
2 medium carrots, minced
2 plum tomatoes, cored and minced
Kosher salt, to taste
3 oz. spinach, trimmed and rinsed (about 2 loosely packed cups)
1 1⁄2 cups canned cannellini beans, rinsed
1 cup fresh or frozen green peas
1⁄2 small head frisée, leaves cut into bite-size pieces (about 2 cups)
Freshly ground black pepper, to taste
Freshly grated Grana Padano or Parmesan, for serving

1. Place half the basil, 2 tbsp. oil, parsley, garlic, and onions in the bowl of a food processor and process until slightly chunky. Heat remaining oil in an 8-qt. pot over medium-high heat and add herb–garlic mixture. Cook, stirring often, until no liquid remains, about 5 minutes. Add potatoes, celery, carrots, and tomatoes. Cook, stirring often, until vegetables are golden brown, about 6 minutes. Add salt, 4 cups water and a piece of Parmesan cheese rind and bring to a boil. Reduce heat to medium-low; cover and cook, stirring occasionally, until vegetables are tender, about 20 minutes.

2. Stir in spinach, beans, peas, and frisée and cook until greens are wilted and just tender, about 10 minutes; season with salt and pepper and stir in remaining basil. To serve, ladle soup into bowls, sprinkle with Grana Padano, and drizzle with oil.