Heat the olive oil in a large pot or Dutch oven over medium heat. Add the onion, carrots, celery and a pinch of salt. Cook, stirring now and then, for 7 to 8 minutes, until the vegetables are soft and the onion is translucent.

Stir in the garlic, tomato paste, oregano, thyme and red pepper flakes (if using). Cook for 1 to 2 minutes, stirring constantly, until the tomato paste darkens slightly and smells fragrant.

Add the diced tomatoes with their juices, vegetable broth, beans, bay leaf, salt and pepper. Bring to a boil, then lower the heat and simmer, partly covered, for 10 minutes.

For a thicker, creamier soup, mash some of the beans against the side of the pot with the back of a wooden spoon.

Stir in the pasta and simmer uncovered, stirring often so it does not stick to the bottom, for 8 to 10 minutes or until the pasta is just tender (check the package time).

Add the kale for the last 3 to 4 minutes of cooking (if using spinach, stir it in during the last minute). Take the pot off the heat, remove the bay leaf and stir in the lemon juice. Taste and add more salt if needed. If the soup is thicker than you like, loosen it with a splash of broth or water.

Ladle into bowls and finish with parsley, a drizzle of olive oil and grated cheese if you like. Serve with crusty bread.