Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Season the chicken breast evenly with dried oregano, garlic powder, and a pinch of the sea salt and black pepper.
Place the chicken on the prepared baking sheet and roast for 20-25 minutes, or until the internal temperature reaches 165°F.
While the chicken is roasting, peel the Yukon Gold potato and cut it into 1-inch chunks.
Place the potato chunks in a pot of salted water, bring to a boil, and cook for 12-15 minutes until fork-tender.
In a small skillet over low heat, melt the ghee and sauté the minced garlic cloves for 1-2 minutes until fragrant and softened.
Drain the potatoes and return them to the pot; add the sautéed garlic with ghee, Greek yogurt, and skim milk.
Mash the potatoes thoroughly until smooth and creamy, then season with the remaining sea salt and black pepper.
Slice the roasted chicken breast into strips and serve it over the warm bed of buttery garlic mashed potatoes.