Preheat the oven to 375°F (190°C). Roast the pheasant breasts for 20-25 minutes, or until cooked through. Let rest and slice into thin strips., Cook the brown rice according to package instructions., Steam the butternut squash and peas until soft., In a mixing bowl, combine the sliced pheasant, brown rice, squash, and peas., Let cool before serving. Store leftovers in the fridge for up to 3 days.