Melt the ghee or coconut oil in a big skillet. Place the mushrooms in with a dash of salt. Saute until these cook down, about 10 minutes. Add onion, garlic, carrots, and chicken broth. Cook on medium high heat until nearly soft. Remove about 1/4 cup of the broth and mushroom liquid into a small bowl, and whisk in the GF flour or tapioca starch, to form a thick smooth paste. Once it is smooth, add it back to the skillet. Continue stirring to thicken the entire mixture. Add the chicken, frozen peas, nutmeg, pepper, and more salt to taste. Turn off heat, and stir to mix all ingredients thoroughly. Cover and set aside.