Preheat your oven to 400°F. Scrub the Russet potato clean, pierce it several times with a fork, and bake for 45-50 minutes until the center is tender.
While the potato bakes, finely dice the yellow onion and sauté it in a non-stick skillet over medium heat until translucent.
Add the ground turkey to the skillet, breaking it apart with a spatula, and cook until fully browned and no pink remains.
Stir in the tomato paste, chili powder, cumin, garlic powder, sea salt, and black pepper. Add a splash of water and simmer for 5 minutes until the mixture is thick and flavorful.
Once the potato is cool enough to handle, slice it in half lengthwise. Scoop out the flesh, leaving about a 1/4-inch thick shell of potato against the skin.
Increase the oven temperature to 425°F. Brush the inside and outside of the potato skins with olive oil and place them cut-side down on a baking sheet.
Bake the skins for 5-7 minutes, then flip them over and bake for another 5 minutes until the edges are golden and crispy.
Divide the turkey chili mixture evenly between the two potato skins and top each with the shredded sharp cheddar cheese.
Return the loaded skins to the oven for 2-3 minutes until the cheese is completely melted and bubbling.
Garnish each skin with a dollop of nonfat Greek yogurt and a sprinkle of fresh chives before serving warm.