Place chicken breast between two sheets of parchment paper and pound to an even half-inch thickness for uniform cooking.
Submerge the chicken in buttermilk in a shallow bowl and allow it to marinate for at least 15 minutes.
In a separate shallow dish, whisk together the whole wheat flour, smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting the excess drip off, then dredge thoroughly in the flour mixture until completely coated.
Lightly brush or spray the chicken with avocado oil and place it in an air fryer basket at 375°F for 12-15 minutes, flipping halfway through, until the exterior is crispy and golden.
While the chicken cooks, whisk the almond milk, arrowroot powder, and chicken broth in a small saucepan over medium heat until it thickens into a smooth gravy.
Steam the green beans until they are tender-crisp and bright green.
Serve the crispy chicken topped with the warm gravy alongside the steamed green beans.