Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Dice the chicken breast into bite-sized 1-inch cubes and pat them dry with a paper towel.
Rinse and drain the chickpeas, then roll them in a clean kitchen towel to remove as much moisture as possible for maximum crispiness.
Place the chicken, chickpeas, broccoli florets, and sliced bell peppers onto the prepared baking sheet.
Drizzle the olive oil over the ingredients and sprinkle evenly with garlic powder, smoked paprika, sea salt, and black pepper.
Toss everything together with your hands or tongs until well-coated, then spread out into a single layer.
Roast in the oven for 20 to 25 minutes, tossing halfway through, until the chicken is cooked through and the chickpeas are slightly golden.
Transfer the roasted mixture to a bowl, top with fresh avocado slices, and drizzle with the lemon juice before serving.