Place the chicken breast in a shallow bowl and cover with 0.25 cup of buttermilk, letting it marinate for 15 minutes.
In a separate shallow dish, whisk together 2 tablespoons of whole wheat flour, garlic powder, onion powder, paprika, sea salt, and black pepper.
Remove the chicken from the buttermilk, allowing the excess to drip off, and dredge it thoroughly in the seasoned flour mixture until coated.
Heat avocado oil in a large skillet over medium heat. Add the chicken and cook for 5-7 minutes per side until the exterior is golden brown and the internal temperature reaches 165°F.
Remove the chicken from the pan and set aside to rest. In the same pan, whisk 1 teaspoon of flour into the remaining oil and drippings for 1 minute.
Slowly pour in the chicken broth and the remaining 2 tablespoons of buttermilk while whisking constantly until the gravy thickens.
Steam the green beans until tender-crisp, about 4-5 minutes.
Plate the chicken, pour the warm gravy over the top, and serve alongside the steamed green beans.