Ingredients

2 tablespoons olive oil
1 medium yellow onion, diced (about 2 cups)
2 medium carrots, peeled and sliced into 1/4 inch pieces (about 2 cups)
3 stalks of celery, sliced into 1/4-inch pieces (about 2 cups; may include leaves)
1 cup diced leeks (optional), white and light green parts only
3 cups peeled butternut squash, cut into 1-inch cubes (may substitute 1 (10-ounce) bag frozen; see notes)
5-6 cups low-sodium chicken broth
1 15-ounce can cannellini beans (or other white bean of choice), rinsed and drained
1 pound cooked chicken breasts, diced or shredded (see notes)
1/2 teaspoon dried thyme leaves
1/8 teaspoon ground sage
Kosher salt and freshly ground pepper
1 cup cream, half and half or coconut milk
Optional: 1 tablespoon cornstarch mixed with a couple tablespoons of the hot broth

Instructions

Heat the oil in a large, heavy-bottomed pot over medium heat. Sauté the onions, celery, carrot, and optional leek until onions are soft, about 10 minutes. Stir in the thyme and sage.
Add the butternut squash and 5 cups of the broth. (If using frozen squash, do not add yet. Reserve the final cup of broth to adjust to your desired thickness at the end.)
Bring the mixture to a boil, and then reduce the heat to a gentle simmer. Cook until the carrots and butternut squash are just tender, about 10-15 minutes.
If using frozen squash, add now that the carrots are tender. Stir in the chicken, white beans, cream or coconut milk, and cook a few minutes more or until heated through. Add the remaining one cup of broth, if desired.
Meanwhile, in a small bowl, mix the optional cornstarch with a few tablespoons of the hot broth. Add to the soup, and stir to incorporate. This will thicken the soup slightly. Add salt and pepper to taste; precise amount will depend upon type of broth (see notes) and personal preference.

For an easy shortcut, you may substitute the fresh butternut squash with one (10-ounce) bag of frozen butternut squash. In this case, stir in the frozen squash just before adding the chicken and beans as it will cook in 4-5 minutes.
An easy way to cook the chicken is to simmer in 6 cups of water for 15-20 minutes, or until just cooked through the middle. This may be done a day or two in advance. Cool, cover and refrigerate until ready to use. Additionally, you may substitute this cooking liquid for the chicken broth called for in the recipe. When I prepared the chicken this way, I added approximately 2 teaspoons of kosher salt and 1/2 teaspoon pepper to match the flavor associated with an already seasoned broth or stock.
As a final option and shortcut, you may add the uncooked chicken along with the carrots, removing and shredding once it is cooked through. In this case, you may need to add a few extra minutes of cooking time until not only the carrots are tender but the chicken is thoroughly cooked.