cups chicken stock or broth
pounds boneless, skinless chicken thighs
leeks, white and light green parts only, halved lengthwise then thinly sliced crosswise (about 2 cups)
carrots, sliced about 1/2-inch thick
celery stalks, sliced about 1/2-inch thick
garlic cloves, minced
teaspoon red-pepper flakes
teaspoon onion powder
Kosher salt and black pepper
lemon, juiced (2 to 3 tablespoons)
cup sliced asparagus (about 12 ounces, trimmed and sliced 1/2-inch thick)
cup fresh or frozen peas
ounces refrigerated spinach-cheese tortellini (optional; see Tip)
cup chopped soft fresh herbs, such as dill, mint, tarragon, parsley, chives or a mixture
- In a 6- to 8-quart slow cooker, combine the stock, chicken, leeks, carrots, celery, garlic, red-pepper flakes, onion powder and several generous grinds of black pepper. Add 1/2 teaspoon kosher salt if using salted stock, 1 teaspoon kosher salt if using low-sodium stock, or 2 teaspoons kosher salt if using unsalted stock. Cover and cook on low until the chicken and vegetables are very tender, about 7 hours.
- Increase the heat to high. Using two forks, tear apart the chicken into bite-size pieces. Add the lemon juice, asparagus, peas and tortellini, if using, to the soup. Cover and cook until the vegetables are tender to crisp-tender, and the tortellini is cooked through, 6 to 7 minutes. Stir in the herbs; season to taste with salt and pepper. Divide among bowls to serve.