Preheat oven to 400°F and line a small baking sheet with parchment paper.
In a small bowl, whisk 4 tablespoons of the whole wheat flour, the baking powder, and a pinch of the sea salt until combined.
Use a fork to cut the cold grass-fed butter into the flour mixture until it resembles coarse crumbs.
Stir in the Greek yogurt until a soft dough forms, then shape into a single round biscuit.
Place the biscuit on the baking sheet and bake for 12-15 minutes until the top is golden brown.
While the biscuit bakes, place the chicken breast in a shallow bowl and cover with the buttermilk to soak for 10 minutes.
In a separate shallow dish, combine the remaining 1 tablespoon of flour with the garlic powder, onion powder, remaining salt, and black pepper.
Remove the chicken from the buttermilk and dredge it thoroughly in the seasoned flour mixture, pressing to adhere.
Heat the avocado oil in a cast-iron skillet over medium-high heat.
Sear the chicken for 5-6 minutes per side until the exterior is crispy and the internal temperature reaches 165°F.
Serve the golden pan-fried chicken immediately alongside the warm, fluffy biscuit.