1. Place baking sheet in top third of oven. Heat oven to 450°F. Brush 9-inch round or 8-inch square baking dish with oil.
2. Pulse Gouda cheese in food processor until finely chopped. Add spinach, eggs, egg whites, ricotta, flour and nutmeg; process 30 seconds or until well combined. Add remaining ingredients except breakfast sausage; pulse to mix. Stir in cooked breakfast sausage by hand.
3. Pour into prepared dish. Bake on preheated baking sheet 25 to 30 minutes or just until center is set.