Preheat your oven to 400°F and line a baking sheet with parchment paper.
Toss the diced sweet potatoes with a tiny drizzle of oil and a pinch of salt, then roast for 20 minutes until the edges are golden and caramelized.
While potatoes roast, heat the olive oil in a large pot over medium heat and sauté the diced onions until soft and translucent.
Add the ground turkey to the pot, breaking it apart with a wooden spoon, and cook until fully browned.
Stir in the chili powder, cumin, sea salt, and black pepper, allowing the spices to toast for about 60 seconds until fragrant.
Pour in the tomato puree and the rinsed black beans, stirring well to combine all ingredients.
Reduce heat to low and let the chili simmer for 10 to 12 minutes to allow the flavors to deepen.
Gently fold the roasted sweet potatoes into the chili pot just before serving.
Ladle the chili into a bowl and finish with a dollop of Greek yogurt for a creamy, high-protein garnish.