Whisk together eggs, cream and seasonings.
Melt butter in a non-stick skillet over medium heat. Pour in egg mixture and gently swirl the pan to spread evenly. Using a rubber spatula carefully lift edges of omelet, allowing uncooked egg to run under. Continue until no runny egg remains on top. Flip omelet (I remove from heat, lay a paper plate over pan and turn over; then slide back into pan).
Lay tomato, avocado, scallions, herbs and cheese down the middle of the omelet. Fold over one side, then slide out of pan onto plate, folding over other side.