Fry the dwarf beans and onion for 4-5 minutes in a wok until soft. Remove from the pan.
Add oil and pour in the egg. As the base starts to firm up, tip in the dwarf beans. Fold over to allow the rest of the egg to cook. Remove from the pan.
Fry the mince to brown with the soy sauce, followed by the tomatoes until cooked through. Serve aside the egg.