Toast the torn bread on a sheet pan at 350°F until dry at edges, about 8 minutes.
Warm 2 tbsp olive oil in a large pot over medium heat.
Sauté onion, celery, and carrots with a pinch of salt until softened, 8–10 minutes.
Stir in garlic and tomato paste. Cook, stirring, until paste darkens slightly, 1–2 minutes.
Add crushed tomatoes, broth, thyme, oregano, red pepper flakes, salt, and black pepper. Bring to a simmer.
Mash 1 cup of the beans with a fork. Add all beans to the pot and stir.
Fold in kale. Simmer gently until tender and flavors meld, 15–20 minutes.
Stir in toasted bread. Simmer 5–8 minutes, adding a splash of broth or water if too thick.
Finish with lemon juice and the remaining 0.5 tbsp olive oil. Taste and adjust seasoning.
Ladle into bowls and top with Parmesan, if using.
Notes
Variation: For a meaty twist, crisp a little diced pancetta with the vegetables. Swap kale with savoy cabbage if you prefer. For gluten-free, use a hearty gluten-free loaf or add extra beans in place of bread. Storage: Ribollita thickens as it chills—loosen with broth or water when reheating.This recipe is an original creation inspired by classic Easy Tuscan Ribollita Soup flavors. All ingredient ratios and instructions are independently developed.