Pre-heat oven on to 350 degrees (later you'll change it to "Broil")

Heat an 8-inch ovenproof skillet over medium-high heat

Coat pan with cooking spray or butter

Add mushrooms and green onions to pan; saut 12 minutes or until mushrooms are nicely browned

In a medium bowl, add the eggs and egg replacement

Add the half and half

Add the Parmesan cheese

Add the thyme and any additional herbs that you like

Add salt and pepper and whisk everything together

Pour the egg/cheese mixture into the same pan with the sauteed mushrooms and green onions

Heat pan over medium heat

Cook, covered, for about 6 minutes or when it is just a little bit liquid-y/runny on the top

At that point, place the pan into the oven and cook on 350 for another 5 - 10 minutes

Once the frittata is completely set and cooked (not runny on top) change the oven temperature to "Broil"

Place the pan on the lowest rack of the oven and broil for about 2 minutes or until a golden brown color forms on the top