Preheat broiler. In a medium saucepan bring the water to boiling. Add sweet pepper halves; boil 3 to 4 minutes or until just tender. Using tongs or a slotted spoon, transfer peppers to a foil-lined baking sheet.
Meanwhile, microwave the frozen quinoa according to package directions.
In a bowl combine the hot cooked quinoa, 1/2 cup of the cheese, 4 tablespoons of the sunflower seeds, the basil, and salt; stir well. Spoon quinoa mixture into pepper halves. Top with the remaining 1/4 cup cheese.
Broil pepper halves 3 to 4 inches from the heat 1 to 2 minutes or until the cheese is melted and starts to brown. Just before serving, sprinkle with the remaining 1 tablespoon sunflower seeds.