Preheat your oven to 400°F and line a small baking sheet with parchment paper.
Peel the russet potato and cut into 1-inch chunks, then place in a pot of cold water with a pinch of salt.
Bring the potatoes to a boil and cook for 12-15 minutes until fork-tender.
Rub the chicken breast with olive oil, garlic powder, and half of the sea salt and black pepper.
Roast the chicken for 18-22 minutes or until the internal temperature reaches 165°F.
While chicken roasts, mince the garlic cloves and sauté them in the grass-fed butter over low heat until fragrant and golden.
Drain the cooked potatoes well and return them to the warm pot.
Add the garlic butter, Greek yogurt, and remaining salt and pepper to the potatoes, then mash until smooth and creamy.
Slice the roasted chicken into strips and serve immediately over the warm mashed potatoes, garnished with fresh chives.