These marinades are super with any meat. I sometimes mix the marinades in a resealable plastic bag, then drop in the meat, seal up the bag, give it all a good squish and pop in the fridge or freezer until I'm ready to use it. Most meat will be good in the fridge for three days or in the freezer for up to three months, still sitting in the marinade.
These little parcels certainly know how to make an entrance. When you serve them, make sure you get your guests to open the parcels themselves, to reveal the steaming mackerel inside. You can use this method with any fish; it’s nice served with a little rice.