Whisk together the eggs and heavy cream in a small bowl. Heat a non-stick pan over medium heat. Melt the butter on the pan. Pour in the egg mixture and cook the eggs for 1 to 2 minutes—or until the eggs are halfway cooked. Sprinkle in your desired toppings into the middle of the omelet. Using a spatula, fold the omelet in half. Cook for another 30 seconds, then slide the omelet to a plate. Serve immediately.