Prepare the following, adding each to the same large bowl as you complete it: Dice 1 large onion (about 2 cups). Peel and cut 3 medium carrots crosswise into ½-inch thick rounds (about 1 ¾ cups). Cut 3 medium celery stalks crosswise into ½-inch thick pieces (about 1 ¼ cups). Mince 3 garlic cloves.

Melt 2 tablespoons unsalted butter or heat 2 tablespoons olive oil in a Dutch oven heavy-bottomed pot over medium heat. Add the onion mixture, 2 ½ teaspoons kosher salt, and ½ teaspoon black pepper. Cook, stirring occasionally, until the onion is translucent, about 5 minutes.

Add 2 (32-ounce) cartons low-sodium chicken broth, 5 sprigs fresh thyme, and 2 dried bay leaves. Increase the heat to medium-high and bring to a boil. Meanwhile, use 2 forks to shred the meat from 1 (2 ½- to 3-pound) rotisserie chicken or 1 pound cooked, boneless chicken into bite-sized pieces (about 3 cups).

Add the chicken and 6 ounces dried extra-wide egg noodles to the soup. Reduce the heat to maintain a gentle simmer and cook until the noodles are just shy of al dente, 6 to 7 minutes or 1 minute less than the package instructions. Meanwhile, finely chop the leaves and tender stems from ½ medium bunch fresh parsley or dill until you have ¼ cup.

Remove and discard the thyme sprigs and bay leaves. Taste and season with more kosher salt as needed. Add the chopped parsley or dill. If using, squeeze the juice from ½ large lemon until you have 2 tablespoons. Add to soup and stir to combine.