Mix all the chopped herbs together and set aside. Break the eggs into a bowl and season.
Heat the oil in a pan over a medium heat. Fry the mushroom for 5 minutes, add the tomatoes and ⅔ the herbs and stir for 2 minutes.
Stir the egg into the mushroom mixture for 1 minute, then cook gently, using a spatula to keep it from sticking to the sides of the pan.
When the omelette is cooked, sprinkle on the remaining herbs and ham, fold the omelette in half and turn out onto a plate.