Peel and cube the potato, then place in a pot of water with the smashed garlic cloves and boil until tender, approximately 15 minutes.
While the potatoes are boiling, season the chicken breast evenly with garlic powder, half of the sea salt, and half of the black pepper.
Heat a non-stick skillet over medium-high heat and sear the chicken breast for 6 to 7 minutes per side until the internal temperature reaches 165 degrees Fahrenheit.
Drain the potatoes and garlic thoroughly, then return them to the warm pot.
Add the ghee, Greek yogurt, remaining sea salt, and remaining black pepper to the pot.
Mash the mixture until completely smooth and creamy, then fold in the finely chopped fresh chives.
Slice the chicken breast and serve it immediately alongside the warm, buttery mashed potatoes.