Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Peel and dice the sweet potato into 1/2-inch cubes, then toss them on the baking sheet with 0.5 tbsp of olive oil, sea salt, and black pepper.
Roast the sweet potatoes for 20-25 minutes, flipping halfway through, until they are tender and caramelized on the edges.
While the potatoes roast, season the chicken breast with garlic powder and sear it in a skillet over medium heat with the remaining 0.5 tbsp of olive oil until cooked through.
Remove the chicken from the pan, let it rest for 5 minutes, then slice it into strips.
In a large mixing bowl, combine the chopped kale and lemon juice, massaging the leaves with your hands for 1-2 minutes until they soften and turn a deep green.
Assemble the bowl by layering the massaged kale, roasted sweet potatoes, and sliced chicken.
Drizzle the tahini over the top and serve immediately while the components are warm.