Preparation - Spray a 10" oven proof skillet with non-stick cooking spray or use a well-seasoned 10" cast iron skillet. Saute the chopped onion in canola oil, over medium heat, for about 10 minutes. Remove from heat. Stir in the mustard. sugar and thyme. In a mixing bowl, whisk the eggs, water, 1/2 cup shredded Swiss cheese, salt and pepper together. Pour the egg mixture into the skillet. Stir the ingredients together and bake in a preheated oven at 375º for 10 minutes. Top with the remaining cheese. Bake for 5 more minutes.