Mix the oil and vinegar and add the chopped vegetables.
Season with salt and pepper, then cover and put aside for at least 30 minutes, longer if you have time.
Thread canapé haggis onto a skewer (with their skins still on), interspersed with some mushrooms, onion and pepper chunks.
Barbecue once the coals are smouldering.
Try to keep the skewers away from the most intense heat of the barbecue and eat once they are piping hot throughout. This will take approximately 5–10 minutes depending on the intensity of your barbecue.
Delicious served with a tomato and chilli dip. You can eat the skins of the haggis or peel them off, as you prefer.