Place the squash halves, cut side down, on a microwave-safe plate. Microwave on high power for 10 to 12 minutes, or until the squash is easily pierced with a fork. Cool until easy to handle. Spoon out and discard the seeds. With a fork, separate the flesh into strands and place in a large bowl. Reserve the squash shells.
Preheat the oven to 350 F.
In a large no-stick skillet, warm the oil over medium heat. Add the peppers, peas, scallions, garlic, oregano, and mint. Sauté for 5 minutes, or until the vegetables are tender.
Stir in the tomato juice and bring to a boil. Stir in the couscous. Cover, remove from the heat and let stand for 5 minutes, or until the couscous is soft. Fluff with a fork.
Add the couscous mixture and the feta to the bowl with the squash. Toss to mix well. Divide among the reserved squash shells. Cover each shell with foil, place in a no-stick baking dish, and bake for 15 to 20 minutes, or until heated through.