Heat the avocado oil in a large skillet over medium-high heat. Sauté the chopped onion for 5 minutes, until it has softened and begins turning golden brown. Transfer the sauteed onion and garlic to the bottom of your crock pot.

Place the skillet back on the stove top and sear both sides of the chicken thighs for 6 minutes per side.

While the chicken is browning, add the chopped yukon gold potatoes, and carrots (and celery if adding) to the slow cooker. Once the chicken has finished browning, add the thighs to the crock pot too.

Pour in the chicken stock and secure the lid of the crock pot. Cook on high heat for 4 hours or low heat for 8 hours. Remove the lid of the crock pot and add in the chopped baby spinach, peas, and tomatoes. Give everything a big stir. Measure out about ½ cup of the broth from the slow cooker and mix in 2 tablespoons of gluten-free all-purpose flour, regular all-purpose flour, or corn starch. Pour this mixture into the crock pot. Replace the lid and cook on high heat for another hour. This extra step helps thicken the stew, which gives it that comforting appeal.

Use tongs to pull the chicken thighs out of the slow cooker and place them on a cutting board. Once they are cool enough to handle, shred the meat to your desired consistency, and discard the bones and skin. Transfer the meat back into the crock pot. You are now ready to serve! Taste the stew for flavor and add salt and pepper to your personal taste. You can also add chicken bouillon for a deeper chicken flavor.

Serve chicken stew in big bowls with crusty bread, garlic bread, or cornbread.