4mediumcarrotspeeled and 1/4-inch diced, about 2 1/2 cups
3mediumcelery stalks1/4-inch diced, about 2/3 cup
1/2mediumyellow oniondiced, about 1/2 cup
1cupbrown ricerinsed and drained (do not swap white rice, as it will cook more quickly and become mushy; you can use wild rice with a similar cook time, though the flavor of the wild rice will be stronger and more earthy)
1 1/2poundsboneless, skinless chicken breasts or thighs
6–8cupschicken stockdivided (be sure to use regular chicken stock, not unsalted, or chicken broth)
6sprigsfresh thymeplus additional for serving
2tablespoonsfresh lemon juiceor more to taste (optional)
Lightly coat a 5-quart or larger slow cooker with nonstick spray. Heat the olive oil in a large, nonstick pan over medium. Add the carrots, celery, and onion, and cook until the vegetables are beginning to soften, about 8 to 10 minutes. Stir in the garlic, salt, and pepper and cook 30 additional seconds. Remove from the heat and transfer to the bottom of the slow cooker.
Add the rinsed brown rice to the slow cooker. Arrange the chicken breasts on top, then pour in 6 cups of the chicken stock. Add the bay leaf and thyme.
Cover and cook on low for 5 to 6 hours or high for 2 1/2 to 3 1/2 hours, until the rice is tender and the chicken is cooked through. To prevent the chicken from becoming dry, check it early. (To check for doneness, insert an instant-read thermometer. The chicken is done when it registers 165 degrees F at the thickest part.) If the chicken finishes cooking before the rice, remove it first so that it does not overcook, then re-cover the slow cooker and continue cooking until the rice is tender. Remove the bay leaf and thyme stems and discard.
Place the chicken on a plate or cutting board and let it cool slightly. With two forks or your fingers, shred the chicken, then return it to the slow cooker. Stir in the lemon juice. If you'd like the soup thinner, add additional stock until you reach your desired consistency. Taste and adjust the seasoning as desired. Serve warm, sprinkled with additional fresh thyme.
Please note that the cook times listed in this recipe can vary depending upon your slow cooker. Mine consistently finishes in this time. Use your best judgement depending upon your slow cooker model. If it is your first time making the recipe, you may want to build in extra buffer time just in case your slow cooker doesn't get as hot as mine and others who see similar cook times.
Refrigerate leftovers for up to 5 days or freeze for up to 3 months. Reheat gently on the stovetop or in the microwave. The soup tends to thicken as it sits, so you may want to thin it with additional water or stock as needed. I also find the lemon loses its punch as the soup sits, so feel free to squeeze a little more onto your freshly reheated leftovers too.