Heat oven to 200C/180C fan/gas 6.
Space the meatballs in a baking tray
and squash each slightly with the palm
of your hand. Roast for 15 mins until
cooked through, then press some
cheese into the top of each. Put back
in the oven for 20 secs-1 min until the
cheese starts to melt.
Meanwhile, split the rolls in half and
very lightly toast. Spread each half with a
little barbecue sauce, then top each with
a cheesy meatball, some onion and some
cornichon. Skewer with a cocktail stick or
mini skewer to hold everything together.