Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Dice the chicken breast and sweet potato into bite-sized cubes, and halve the Brussels sprouts.
Place the chicken, potatoes, and sprouts on the baking sheet, then toss with olive oil, sea salt, black pepper, garlic powder, and smoked paprika.
Roast for 20 to 25 minutes, tossing halfway through, until the chicken is cooked through and the vegetables are golden brown.
While roasting, place the chopped kale in a bowl with half of the lemon juice and massage with your hands for 1 minute until softened.
In a small jar, whisk together the tahini, remaining lemon juice, and a teaspoon of warm water until smooth and pourable.
Assemble the bowl by placing the roasted chicken and vegetables over the massaged kale and drizzling with the lemon-tahini dressing.