Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Peel the sweet potato and cut into 1/2-inch cubes.
Toss the sweet potato cubes with olive oil, half the sea salt, and half the black pepper on the prepared baking sheet.
Roast for 20-25 minutes, flipping halfway through, until the edges are golden brown and the centers are tender.
While the potatoes roast, dice the chicken breast into bite-sized pieces.
Heat a non-stick skillet over medium-high heat and add the chicken and ground beef.
Season the meat with the remaining sea salt, black pepper, and garlic powder, cooking until the chicken is opaque and the beef is fully browned.
In a small bowl, whisk together the Greek yogurt and cottage cheese until well combined and relatively smooth.
Transfer the roasted sweet potatoes to a serving bowl and top with the cooked chicken and beef mixture.
Add a generous dollop of the yogurt-cheese mixture and garnish with chopped fresh chives before serving.