Chop zucchini in half (so that it's semi-circle-shaped)and then slice thinly.
Put onion in a small pan and cover with water. Bring to a simmer and cover for 10-15 minutes - until cooked.
While the onions are cooking, steam zucchini. (If you prefer, you can saute them).
Beat eggs and season with salt,pepper and mint.
Drain onion and add it and the zucchini to the eggs. Mix well.
Heat a nonstick pan (or use a tsp olive oil) over high heat. Pour the mixture into the pan and cook through in the same way you would scramble eggs - 'scrape' cooked eggs off the bottom and let uncooked liquid fall udnerneath.