Preheat your oven to 400°F (200°C).
Peel the russet potato and cut it into 1-inch chunks. Place them in a pot of cold salted water.
Bring the water to a boil and cook the potatoes for 12-15 minutes until they are fork-tender.
While the potatoes boil, mince the garlic clove and finely chop the chives and parsley.
Pat the chicken breast dry and rub it with olive oil, half of the minced garlic, and a pinch of sea salt and black pepper.
Place the chicken on a parchment-lined baking sheet and roast for 18-22 minutes, or until the internal temperature reaches 165°F.
Drain the cooked potatoes and return them to the warm pot. Let them steam for 1 minute to remove excess moisture.
Add the ghee, Greek yogurt, the remaining minced garlic, sea salt, and black pepper to the pot.
Mash the potatoes until smooth and creamy, then stir in the fresh chopped chives.
Slice the roasted chicken breast and serve it immediately over the warm, buttery garlic mashed potatoes, garnished with fresh parsley.