Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Drain and rinse the chickpeas, then pat them very dry with a clean kitchen towel to ensure they get crispy during roasting.
Dice the chicken breast into uniform 1-inch cubes and thinly slice the red bell pepper into strips.
Place the chicken, chickpeas, broccoli florets, and bell pepper onto the prepared baking sheet.
Drizzle the olive oil over the ingredients and sprinkle evenly with sea salt, black pepper, garlic powder, and smoked paprika.
Toss everything thoroughly with your hands or tongs to ensure an even coating of oil and spices, then spread into a single layer.
Roast in the center of the oven for 20-25 minutes, tossing halfway through, until the chicken is cooked through and the chickpeas are golden.
Remove from the oven and immediately drizzle with fresh lemon juice to brighten the flavors before serving in a shallow bowl.