Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Dice the sweet potato into half-inch cubes and cut the broccoli into small, uniform florets.
Rinse the chickpeas thoroughly in a colander and pat them completely dry with a clean kitchen towel.
Cut the chicken breast into one-inch bite-sized pieces.
Place the chicken, sweet potatoes, broccoli, and chickpeas onto the prepared baking sheet.
Drizzle the olive oil over the ingredients and sprinkle with sea salt, black pepper, garlic powder, and smoked paprika.
Use your hands or a spatula to toss everything together until the spices are evenly distributed.
Spread the mixture into a single layer, ensuring the pan is not overcrowded so the vegetables roast rather than steam.
Roast for 20 to 25 minutes, tossing halfway through, until the chicken is cooked through and the sweet potatoes are fork-tender.
Remove from the oven and squeeze fresh lemon juice over the entire tray before serving in a bowl.