3 tablespoons olive oil
1 cup finely chopped onion
4 cloves garlic
5 cups vegetable stock
1 can (28-ounce) plum tomatoes, coarsely chopped, with juice
4 small red-skinned potatoes (about 10 oz total), cut into 1/2-inch dice (about 2 cups)
2 cups chopped green beans in 2-inch lengths (about 8 oz)
2 carrots, cut into 1/4-inch slices
1 zucchini, halved lengthwise and cut into 1/4-inch slices
2 tablespoons minced fresh oregano or 2 teaspoons dried oregano
1 can (15-ounce) cannellini beans, drained and rinsed
3 ounces spaghetti (3/4-inch bundle), broken into 2-inch pieces
1 can (6-ounce) tomato paste
1/4 cup finely chopped fresh flat-leaf parsley
1/4 cup finely chopped fresh basil or 2 teaspoons dried basil
1/2 teaspoon freshly ground pepper
, or to taste salt
, to taste
thinly shaved Parmesan cheese for garnish
Heat the oil in a Dutch oven over medium heat. Add the onion and half of the minced garlic; cook, stirring occasionally, until the onion is translucent, about 5 minutes. Add the vegetable stock, tomatoes with juice, potatoes, green beans, carrots, zucchini, and oregano. Increase the heat to high and bring to a boil. Reduce the heat; cover and simmer, stirring occasionally, until the vegetables are almost tender, about 25 minutes.
Increase the heat to high and bring to a boil. Stir in the cannellini beans and spaghetti. Reduce the heat; cover and cook until the spaghetti is tender, about 12 minutes.
Stir together the tomato paste, parsley, basil, pepper, and the remaining minced garlic; whisk into the soup. Add about 1/2 cup of the soup liquid and stir until smooth. Gently stir this mixture into the soup. Taste and adjust the seasoning.
Ladle into large soup bowls and garnish with Parmesan.