Slice the chicken breast into even strips and place them in a bowl with the buttermilk to marinate for at least 20 minutes.
In a shallow dish, combine the whole wheat flour, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Remove each chicken strip from the buttermilk, letting the excess drip off, and dredge thoroughly in the seasoned flour mixture.
Lightly spray or brush the chicken strips with avocado oil and place them in the air fryer basket at 400°F.
Air fry for 12 to 15 minutes, flipping halfway through, until the coating is golden brown and the chicken is cooked through.
While the chicken cooks, whisk the almond milk, arrowroot powder, and dried thyme in a small saucepan over medium heat.
Whisk the gravy constantly until it simmers and thickens into a smooth consistency, then season with an extra pinch of salt if desired.
Plate the crispy chicken strips and drizzle the warm, creamy gravy over the top before serving.