Preheat your oven to 400°F.
In a small bowl, mix the lemon juice, minced garlic, salt, and pepper. Rub this mixture evenly over the chicken breast.
Cut the sweet potato into small cubes and toss with a splash of olive oil, salt, and pepper.
Place the chicken breast and sweet potato cubes on a baking tray lined with parchment paper. Roast in the oven for about 20-25 minutes or until the chicken is cooked through and the sweet potato is tender.
While the chicken and sweet potatoes roast, toss the kale with a drizzle of olive oil, salt, and pepper. Spread the kale on another baking sheet.
During the last 7-10 minutes of roasting, place the kale in the oven and bake until crispy.
Once everything is cooked, plate the chicken, sweet potatoes, and crispy kale together. Optionally, drizzle any remaining pan juices over the chicken for extra flavor.