Pre heat oven to 350.

Trim asparagus and cut into 1-inch pieces on the bias (aka on a diagonal) and steam for 3-4 minutes in the microwave.

In a large bowl combine egg, egg whites, Swiss cheese, Parmesan cheese, milk and season with salt and pepper.

Heat butter in a 12-inch skillet and add onion. Saut the onion for 5 minute or until it's fragrant and translucent. Stir in the asparagus and season with salt and pepper.

Turn off the heat and pour egg mixture into the pan with the veggies. Pop the pan into the oven for 18-20 minutes or until just cooked through. Cool and enjoy!