Melt the butter in a large skillet over medium heat. Add onion, bell pepper, and garlic powder, to taste, and cook for 5 minutes. Add peas and rice and cook an additional 10 to 15 minutes. Be careful not to overcook; this dish is best if the bell pepper and onion still have a crunch to them. Season with salt and pepper to taste. Garnish each serving with sprig of parsley.