Peel the russet potato and chop it into uniform 1-inch cubes for even cooking.
Place the potato cubes in a pot of cold water with a pinch of sea salt, bring to a boil, and cook for 12-15 minutes until fork-tender.
While the potatoes boil, season the chicken breast on both sides with garlic powder, sea salt, and black pepper.
Heat the avocado oil in a skillet over medium-high heat and sear the chicken for 6-7 minutes per side until the internal temperature reaches 165 degrees Fahrenheit.
Mince the garlic cloves and finely chop the fresh chives.
Drain the cooked potatoes and return them to the warm pot for 1 minute to allow excess steam to escape.
Add the ghee and minced garlic to the potatoes, then mash thoroughly until the mixture is smooth and fluffy.
Fold in the Greek yogurt to add creaminess and a protein boost, then stir in the fresh chives.
Slice the seared chicken breast and serve it immediately alongside the warm, buttery garlic mashed potatoes.