• Preheat oven to 190ºC (375ºF).
• Butter the bottom and edges of an 8- or 9-inch cast iron pan. Add parmesan and turn the pan so that it is evenly distributed in the bottom and on the edges of the pan. Set aside.
• In a mixing bowl, put the eggs, milk, cream, flour, baking powder and onion salt. Blend for 1-2 minutes, or until smooth.
• Pour into the pan.
• Bake for 25 to 30 minutes.
• Take out of the oven and serve immediately.

Secret de chef : Putting Parmesan cheese in the buttered skillet helps the omelet puff (the cheese helps the egg mixture to cling to the edge and stay puffed up), in addition to giving it flavor.