Preheat your oven to 400°F and line a small baking sheet with parchment paper.
Scrub the Russet potato thoroughly, pierce it several times with a fork, and bake for 45 to 50 minutes until the center is tender.
While the potato is baking, heat a non-stick skillet over medium heat and add the ground beef, diced red onion, and green bell pepper.
Sauté the beef mixture until the meat is fully browned and the vegetables are softened, then drain any excess liquid.
Stir the sea salt, black pepper, and garlic powder into the beef mixture and set aside.
Once the potato is done, let it cool slightly, then slice it in half lengthwise.
Scoop out the potato flesh, leaving about a 1/4-inch thick shell of potato against the skin.
Brush the inside and outside of the potato skins with olive oil and place them back in the oven for 5 minutes to crisp up.
Remove the skins from the oven, fill them evenly with the beef and vegetable mixture, and sprinkle the shredded cheddar cheese on top.
Return the filled skins to the oven for 2 to 3 minutes until the cheese is completely melted and bubbly.
Garnish each potato skin with a dollop of Greek yogurt and a sprinkle of fresh chives before serving.