Preheat your oven to 400°F and line a large baking sheet with parchment paper to prevent sticking without extra grease.
Wash the kabocha squash and cube it into 1-inch pieces, keeping the skin on as it becomes perfectly tender and edible when roasted.
Seed and dice the poblano pepper into bite-sized pieces and cut the chicken breast into similar 1-inch chunks.
In a large mixing bowl, combine the squash, poblano, and chicken, then toss thoroughly with olive oil, sea salt, black pepper, smoked paprika, and garlic powder.
Spread the mixture across the baking sheet in a single layer, ensuring there is space between the pieces so they roast and develop a golden color.
Place in the oven and roast for 20 minutes, then remove the tray and sprinkle the raw pepitas over the top of the mixture.
Return the tray to the oven for an additional 5 to 7 minutes until the chicken is cooked through and the pepitas are toasted and fragrant.
Remove from the oven and immediately drizzle with fresh lime juice to cut through the earthiness of the squash before serving.