Just coming into season, mackerel is an oily fish, rich in saturated fat, cholesterol and omega-3 fatty acids, and a good source of selenium, and vitamin B12. Combined with cream cheese, perfect for a light, satiating lunch.
As with all fish, seek out a fresh catch - the fish should not smell of fish, should have bright eyes and a firm texture. Mackerel should not droop when held by the head.
Cream cheese should be as natural as you can get it - there really is no need to buy industrialised cream cheese which may have all manner of preservatives, emulfisiers and so on. If in doubt, check the ingredients! If you're still in doubt, rely upon what I call the Ingredient/Description Principle, as outlined in Coming in From the Cold on my personal paleo blog.
Interestingly enough, Philadelphia brand has Locust Bean Gum listed in the ingredients (urgh!), yet (one for the UK paleo people), Sainsbury own brand "So Organic" Cream Cheese does not even list ingredients on the tub - it is, literally, "cream cheese".
Simply put, the ingredients should list nothing more than the description of the food; so, 'Butter' should read as "butter" in the ingredients, 'Salted Butter' as "butter, sea salt" and ... 'Cream Cheese' as "cream cheese". Anything else in there are you probably don't want to eat it, particularly if it has an x in it!
Of course you could make the cream cheese yourself by hanging some full fat yoghurt up in a muslin bag and permitting the whey to drain out.
To work ...
Take the fish whole, gut it by slitting the belly where you feel the underside go soft through to the tail. Remove the guts and wash out the cavity. Fillet.
To fillet, lay the fish flat on a board. With a sharp knife, cut towards the head just behind the little fin on the side. Turn the knife so that the blade is now pointing towards the tail and slide it through the flesh using the rib cage as a natural level. That's your fillet.
Now, feel the fillet. There are still bones in the middle section. You could painstakingly pick them all out with tweezers, which will leave your fillet looking like the cat has already had a go at it! Or, you could slice that little ridge of bones out in a V shape which will leave the fillet with two visible sides.
Pop them on the grill or under the grill/broiler for literally a couple of minutes until the surface can be seen to be bubbling. The remainder of the carcass can also be cooked in the same manner - I usually just remove the head and place the skeleton in alongside the fillets, picking off the last pieces of meat afterwards ... or, just letting the cats at it.
Once cooked, remove from under the grill/broiler and set aside to cool.
Once cooled, remove the fish flesh from the skin and break up the fibres with your fingers.
Simply cream some lemon juice and the cream cheese together until smooth and then fold the fish in. Whip these together until you have a soft paste.
Grind a good helping of black pepper over and perhaps a little sea salt.
Stir together well and turn out into a ramekin.
Spread onto gem lettuce leaves.
Alternatives | Variations
If cream cheese is not part of your paleo template, you can just leave it out and enjoy the fish with lemon juice, perhaps some minced capers ... or, blend some avocado and combine with the fish.
I would guard against mixing with coconut oil or dripping since these will solidify again when cooled although this would work very well for a warm pâté - fish straight from under the grill/broiler, shredded and stirred together with coconut oil and served immediately.