Place the chicken breast in a bowl and cover with buttermilk; allow to marinate for at least 20 minutes in the refrigerator.
In a shallow dish, whisk together 1.5 tablespoons of the flour with the smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, allowing the excess to drip off, then dredge it thoroughly in the seasoned flour mixture until well-coated.
Heat the avocado oil in a non-stick skillet over medium heat and cook the chicken for 5-6 minutes per side until the exterior is crispy and the internal temperature reaches 165°F.
Remove the chicken from the pan and set aside on a plate.
Whisk the remaining 0.5 tablespoon of flour into the remaining pan drippings and cook for 1 minute to form a roux.
Slowly pour in the milk while whisking constantly, add the dried thyme, and simmer until the gravy has thickened into a smooth consistency.
Serve the crispy chicken immediately topped with the warm creamy gravy.