In a large bowl combine ground turkey breast, onion powder, black pepper, sage, nutmeg, crushed red pepper, and marjoram; mix well. In a large skillet cook turkey mixture over medium heat until brown.
Lightly coat a 3-quart rectangular baking dish with cooking spray. Cut English muffins into quarters; arrange in an even layer in baking dish. Sprinkle cooked turkey mixture evenly over English muffins.
In a large bowl whisk together eggs, milk, dry mustard, salt, and paprika; pour over layers in dish. Sprinkle sweet peppers and green onions over egg mixture. Cover and chill for 8 to 24 hours.
Preheat oven to 350 degrees F. Bake, uncovered, for 45 minutes. Sprinkle with cheese. Bake, for 5 to 10 minutes more or until a knife inserted near the center comes out clean. Let stand for 10 minutes before serving.