Preheat your oven to 400°F (200°C). Scrub the Russet potato clean and prick it several times with a fork.
Place the potato directly on the oven rack and bake for 45-50 minutes until the skin is crisp and the inside is tender.
While the potato bakes, heat a non-stick skillet over medium-high heat. Add the ground turkey and cook until browned, breaking it into small crumbles.
Stir in the tomato puree, chili powder, ground cumin, garlic powder, sea salt, and black pepper. Simmer for 5 minutes until the sauce has thickened, then set aside.
Once the potato is done, remove it from the oven and let it cool slightly. Slice it in half lengthwise.
Scoop out most of the potato flesh, leaving about a 1/4-inch thick shell. Save the extra potato for another use.
Brush the inside and outside of the potato skins with olive oil. Place them cut-side down on a baking sheet and bake for 5-7 minutes to crisp up.
Flip the skins over and fill each half with the prepared turkey chili. Sprinkle the shredded sharp cheddar cheese evenly over the top.
Return to the oven for 2-3 minutes or until the cheese is completely melted and bubbling.
Remove from the oven and top each skin with a dollop of plain Greek yogurt and a sprinkle of sliced green onions before serving.