Firstly chop the courgettes. I like these smallish pieces you can see in the photo but you could equally do half moon slices or whole slices.
Put them into two equalish piles and set aside.
Heat the oil in a wok for a few minutes until a mustard seed fizzles and pops when added.
Add all the mustard seeds and let them fizzle a bit before adding one of the piles of courgettes.
Add the salt and spices and stir roughly with a fork or chopsticks and then stir in the lemon juice and zest.
Cover and leave to simmer for about 5 minutes. The courgettes should be nice and soft.
Stir in the other pile of courgettes, check the salt seasoning and add more as you wish.
Leave uncovered for another 3 minutes and then take it off the heat.
Chop the mint leaves and add these in.
That's it. All done.