Place the chicken breast in a shallow bowl and pour the buttermilk over it, ensuring it is fully submerged; let it marinate for at least 20 minutes.
In a separate shallow dish, whisk together the almond flour, arrowroot powder, garlic powder, onion powder, paprika, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting excess drip off, then dredge it thoroughly in the flour mixture until evenly coated.
Heat the avocado oil in a large skillet over medium-high heat. Once hot, add the chicken and cook for 5-6 minutes per side until the crust is golden brown and the internal temperature reaches 165°F.
While the chicken cooks, whisk together the Dijon mustard, honey, and Greek yogurt in a small bowl to create the honey mustard sauce.
Steam the green beans for 4-5 minutes until tender-crisp and bright green.
Serve the crispy chicken alongside the steamed green beans with the honey mustard sauce on the side for dipping.