Preheat the oven to 425°F. Line a large baking sheet with parchment paper.
Place the cubed butternut squash and chicken pieces in a large bowl. Drizzle with olive oil, then sprinkle with salt, pepper, garlic powder, and thyme. Toss until everything is evenly coated.
Spread the squash and chicken in a single layer on the prepared baking sheet. Roast for 25 to 30 minutes, stirring once halfway through, until the squash is tender and the chicken is cooked through.
While the squash and chicken roast, cook the rice according to package directions in a medium pot. Fluff with a fork once done.
Divide the cooked rice among four bowls. Top each bowl with the roasted squash and chicken. Sprinkle with chopped parsley and roasted pumpkin seeds before serving.