Add chicken to a medium pot. Add water to cover the chicken. Bring to a boil, and then reduce to medium heat. Cook the chicken for about 15 minutes, or until the internal temperature reaches 165 degrees. Remove chicken from pot and allow to cool for 5 minutes before shredding it up. Tip: I like to cut the chicken up before boiling it to make it cook faster.
In a large pan, melt butter over medium high heat. Once melted, add flour, onion powder and thyme, mixing to combine. Add in the chicken broth, a little bit at a time, whisking it until it's smooth. Bring to a boil, and then reduce to simmer, making sure to continue mixing it to thicken, about 2-3 minutes.
Add shredded chicken to pan, and cook for a couple more minutes, mixing until you have a creamy chicken and gravy mixture.