As mackerel is an oily fish, it is advisable to soak your fillets in a saline solution for 20 minutes before smoking them as this helps to dry the fish out a little which helps the smoking process and improves the flavour of the fish.
This is also true for other oily fish such as salmon. Non oily fish can simply be seasoned with a little salt before smoking.
Make a saline solution by mixing salt with water. The video below demonstrates how to make a saline solution using the optimal quantities of salt and water.
Remove the rack and put a heaped tablespoon of your chosen wood chips into the bottom of the oven and then replace the rack.
Remove raw mackerel fillets (or a whole gutted fish) from the brine and pat dry. Place on rack and close lid of the oven making sure it is tightly shut.
Put the oven on any heat source such as a hob, BBQ or outdoor burner and leave to smoke. Mackerel fillets will take approximately 10 minutes.
Slowly remove the lid and allow the smoke inside to desperse. Take care as the oven will be hot! Remove the cooked fillets (or fish) from the rack and enjoy!