Put first three ingredients in a medium-sized bowl and beat with hand-held beater until completely mixed and slightly frothy. Set aside. Heat at medium heat a 9-inch non-stick fry pan and melt the butter in the pan until it sizzles. Tilt the pan to grease all areas. Pour in egg mixture and cover for one minute.
Remove cover and take a heat resistant spatula and slightly lift the edges of the egg, a portion at a time, allowing the wet egg to spread out and go under the cooked portion. Cover, again, for about 30 – 45 seconds.
When the egg is set, layer the sausage, onions and cheese on half of the circle of egg. Season with pepper to taste, and then take the spatula and work up edge of the empty side of the egg. Fold this side over the filled half. Cover and let the omelet cook about 30 seconds.
Arrange on the plate the orange slices, strawberry and croissant and serve with a smile.
Remove the omelet from the pan by tipping the pan, sliding the omelet onto a serving plate. Sprinkle with tomatoes.