Build the flavor base – Heat the olive oil in a large pot over medium heat until it shimmers. Add the chopped onion, carrots, and celery, then sauté gently for 6–8 minutes. Stir often and allow the vegetables to soften slowly without browning. This step creates the foundation of the soup and brings out natural sweetness from the vegetables.

Release aromatics – Add the minced garlic, dried thyme, dried oregano, and red pepper flakes. Stir continuously for about 30–45 seconds until the herbs become fragrant. Keep the heat moderate to prevent the garlic from burning, as this stage sets the aromatic tone for the entire soup.

Create depth – Stir in the tomato paste and cook it for a full minute, pressing it against the bottom of the pot as you stir. This step caramelizes the tomato paste slightly, removing its raw edge and adding richness and color to the soup.

Form the broth – Pour in the diced tomatoes along with their juices, followed by the stock. Stir well to loosen any flavorful bits stuck to the bottom of the pot. Bring the mixture to a gentle boil, allowing the flavors to begin melding together.

Add hearty vegetables – Stir in the cannellini beans, diced squash or potatoes, and green beans. These ingredients give the soup its body and substance, making it filling and satisfying without feeling heavy.

Simmer gently – Reduce the heat to low and let the soup simmer uncovered for 20–25 minutes. Stir occasionally and allow the vegetables to cook until tender but not mushy. The broth will thicken slightly as the vegetables release their starches.

Cook the pasta – Add the pasta during the final stage of cooking and simmer until just al dente. Stir occasionally to prevent sticking. Cooking the pasta directly in the soup allows it to absorb flavor while keeping the texture balanced.

Finish fresh – Stir in the spinach or kale and cook for 1–2 minutes until just wilted. Season with salt and black pepper to taste, then remove from heat and garnish with freshly chopped parsley before serving.