Method
- Set a large 6-quart pot over medium heat and add the 3 tablespoons of olive oil, letting it warm for about 30 seconds until it shimmers slightly.
- Add the diced onion, carrots, and celery to the pot. Cook for 6 to 8 minutes, stirring occasionally, until the onion turns soft and translucent and the vegetables smell sweet rather than raw.
- Add the minced garlic and diced zucchini, stirring for 1 minute until the garlic is fragrant but not browned.
- Pour in the diced tomatoes with their juices and the broth. If using a Parmesan rind, drop it in now - it will slowly release savory flavor as the soup simmers.
- Add the dried Italian seasoning and the salt, then raise the heat to high and bring the soup to a boil.
- Once boiling, reduce the heat to medium-low so the soup simmers gently with small, steady bubbles. Cover with the lid slightly ajar and cook for 15 minutes to let the vegetables soften and the flavors combine.
- Stir in the drained cannellini beans and chopped cabbage or kale. Continue simmering uncovered for 8 to 10 minutes, until the greens have wilted and softened but still hold a bit of texture.
- Add the small pasta and cook for 8 to 10 minutes, stirring occasionally to prevent sticking, until the pasta is tender but still has a slight bite (check the package time as a guide, since pasta shapes vary).
- Check the carrots by piercing one with a fork - it should slide in easily with just a little resistance, showing the vegetables are fully cooked.
- Fish out and discard the Parmesan rind if you used one; it has done its job flavoring the broth and is too tough to eat.
- Taste the soup carefully (let a spoonful cool first) and add more salt if needed, keeping in mind the Parmesan you sprinkle on top will add extra saltiness too.
- If the soup thickens too much as the pasta sits (this happens quickly), stir in an extra splash of broth or water to loosen it back to a good soupy consistency.
- Ladle the minestrone into bowls, drizzle each with a little extra olive oil, and top generously with grated Parmesan cheese before serving.
Tips
Save Parmesan rinds in the freezer specifically for soups like this one - they melt into the broth as it simmers and add a savory depth that is hard to get any other way.
If you are not serving all the minestrone right away, cook the pasta separately and add it to individual bowls, since it keeps absorbing broth and turns soft and swollen in the fridge overnight.