Heat a chargrill pan over high heat, add the whole capsicums and cook until blackened (you may need to do this in batches, depending on the size of your pan). Transfer to a zip lock bag or place in a bowl and cover with plastic wrap. Set aside to steam for about 10 minutes.
Remove the skins from the capsicums and slice the flesh into 1 cm thick strips.
Transfer to a bowl and add the remaining ingredients, tossing well to combine.
Set aside in the fridge for at least 1 hour, but it will taste even better if left until the next day.