Customizable Vegetable Soup

In a large pot, heat oil over medium-high. Add onion, garlic, carrot, and celery. Season with salt and cook, stirring, until onion is translucent, about 3 minutes.
Stir in oregano or thyme and/or tomato paste or Parmesan rind.
Pour in 8 cups low-sodium chicken broth, vegetable broth, or water.
Stir in hard, starchy vegetables. Bring to a boil, then reduce to a simmer and cook 5 minutes.
Stir in quick-cooking vegetables. Return to a boil, then reduce to a simmer and cook 5 minutes more.
Stir in rice, pasta, or canned chickpeas or other beans or legumes, and greens. Heat through. Adjust seasoning with salt as desired.
Ladle soup into bowls. Drizzle with oil; sprinkle with Parmesan and herbs. Serve with crostini.

Ingredient :

2 tablespoons extra-virgin olive oil, plus more for drizzling
1 cup chopped onion or other allium (leeks, shallots, scallions)
1 tablespoon minced garlic (from 3 cloves)
¾ cup diced carrot
½ cup diced celery
Kosher salt
1 teaspoon dried oregano or thyme (or 2 to 3 sprigs fresh), optional
1 tablespoon tomato paste, optional
1 Parmesan rind (optional), plus finely grated Parmesan for serving
2 cups peeled and diced hard, starchy vegetables, such as potatoes, parsnips, turnips, or squashes
8 cups low-sodium chicken or vegetable broth, or water
1 to 2 cups quick-cooking vegetables cut into bite-size pieces, such as green beans, broccoli, zucchini, peas, and/or corn
1 cup cooked rice, pasta, or canned chickpeas or other beans or legumes
1 to 2 cups chopped leafy greens, such as spinach, arugula, kale, or Swiss chard
Fresh herbs, such as flat-leaf parsley or basil, for serving
Simple Crostini, for serving