In a large soup pot over medium heat, add the olive oil and butter. When the butter has melted and the oil is shimmering, add the diced onion, carrots, and celery. Cook, stirring occasionally, until the onion is translucent and the vegetables begin to soften, about 6–8 minutes.

Add garlic and deglaze

Add the minced garlic and cook for 30–45 seconds until fragrant. If using, pour in the white wine and let it reduce by half, scraping any browned bits from the bottom of the pot, about 1–2 minutes.

Add liquids

Pour in the broth and water. Stir to combine and bring to a gentle simmer.

Aromatics and vegetables

Stir in the diced zucchini and the undrained canned diced tomatoes. Add the oregano, thyme, bay leaf, salt, pepper, and red pepper flakes (if using). If you included the Parmesan rind, add it now.

Reduce heat to maintain a gentle simmer and cook until the carrots and zucchini are tender, about 12–15 minutes.

Legumes, pasta & add-ins

Add the drained cannellini beans and the small pasta directly to the simmering soup. Stir and continue to simmer, uncovered, until the pasta is al dente (check package directions; typically 8–10 minutes) and the beans are heated through.

If the soup becomes too thick as the pasta swells, add up to 1 cup extra broth or water to reach desired consistency.

About 2 minutes before the pasta finishes, stir in the spinach or chopped kale so it wilts but remains bright.

Herbs, seasoning & finish

Remove the bay leaf and Parmesan rind (if used). Taste and adjust seasoning with additional salt and pepper as desired. Stir in the lemon juice if using.

Ladle the soup into bowls. Sprinkle each serving with chopped fresh parsley and a generous grating of Parmesan. Serve hot with crusty bread.