Place the chicken breast in a shallow bowl and pour the buttermilk over it, ensuring it is fully coated; let it marinate for at least 15 minutes.
In a separate small plate, whisk together the whole wheat flour, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting the excess drip off, and dredge it through the seasoned flour until evenly coated.
Heat the avocado oil in a non-stick skillet over medium-high heat. Once hot, add the chicken and cook for 5-6 minutes per side until the crust is golden and the internal temperature reaches 165 degrees Fahrenheit.
While the chicken cooks, whisk together the Dijon mustard and honey in a small ramekin to create the sauce.
Steam the broccoli florets in a steamer basket over boiling water for 3-4 minutes until tender-crisp and bright green.
Serve the crispy chicken alongside the steamed broccoli with the honey mustard sauce on the side for dipping.