Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Peel and dice the butternut squash into 1/2-inch cubes, and cut the chicken breast into bite-sized pieces.
Rinse and drain the chickpeas, then pat them dry with a paper towel to ensure they get crispy in the oven.
In a large bowl, combine the squash, chicken, and chickpeas. Drizzle with olive oil and sprinkle with smoked paprika, garlic powder, sea salt, and black pepper.
Toss everything together until evenly coated, then spread the mixture in a single layer on the prepared baking sheet.
Roast for 20-25 minutes, tossing halfway through, until the chicken is cooked through and the squash is tender and caramelized.
Place the fresh baby spinach in a serving bowl and top with the warm roasted chicken and vegetable mixture.
Drizzle the entire bowl with fresh lemon juice just before serving to brighten the flavors.