Tuscan Ribollita with Summer Vegetables

Ingredients

• 3 tablespoons extra-virgin olive oil, plus more as needed
• 3 medium cloves garlic, thinly sliced
• 1 medium yellow onion, thinly sliced
• 1 large leek, white and light green parts only, diced
• 2 large carrots, peeled and diced
• 3 large celery stalks, diced
• Kosher salt
• 2 to 3 sprigs fresh rosemary or thyme
• 1 tablespoon tomato paste
• Water
• 2 bay leaves
• 1 chunk Parmigiano-Reggiano rind, about 2 inches squared, optional
• 2 medium zucchini, cut into bite-size pieces
• 2 medium summer squash, cut into bite-size pieces
• 8 ounces green beans, cut into 1-inch pieces
• 4 ounces spinach, roughly chopped
• 1 cup roughly chopped fresh basil leaves
• Freshly ground black pepper
• 1/4 pound fresh or stale rustic crusty bread, cut into 1-inch cubes
• Freshly grated Parmigiano-Reggiano, for serving, optional

Directions

1. Set a large Dutch oven or soup pot over medium-low heat, then add the olive oil and garlic. Stir as the garlic cooks, stopping when it smells sweet and turns just pale gold. Add the onion, leek, carrots, celery, and rosemary or thyme sprigs, then season lightly with salt. Cook, stirring now and then, until the vegetables are completely soft but have not taken on color, about 10 minutes; pour in a little more oil if the bottom of the pot starts to look dry.
2. Stir in the tomato paste until it blends into the vegetables, about 30 seconds. Pour in 6 cups of water, then add the bay leaves, Parmesan rind, zucchini, summer squash, green beans, spinach, and basil. Bring everything to a gentle simmer and cook, stirring often, until the vegetables are tender all the way through, about 10 minutes. Taste and adjust with salt and pepper.
3. Add the bread and stir thoroughly. Continue simmering until the bread turns very soft and starts to fall apart, about 15 minutes. If the soup gets too thick or dry, loosen it with water, adding 1/2 cup at a time.
4. Taste once more and season with salt, pepper, and a generous shaving of Parmesan, if using. You can stop while it is loose and brothy, serve it as a thick, chunky soup, or keep cooking until it becomes dense and porridge-like. When it has reached that thick porridge stage, spoon some into an 8-inch nonstick skillet slicked with 1 tablespoon oil. Cook over medium-high heat, stirring often, until it gathers into a compact mass and eventually forms a pancake shape. If you are comfortable flipping it, turn it over so the browned side faces up for serving. Slide it out onto a plate.
5. However you serve it, remove the bay leaves, rosemary or thyme sprigs, and Parmesan rind first. Finish with a drizzle of fresh olive oil, freshly ground black pepper, and more grated cheese, if you like.