More of a main course really, and ideally would be labelled as "Mackerel Fillet with rhubarb & ginger compote, on sour-dough roll garnished with truffle oil dressed rocket, & raspberry balsamic vinaigrette". Either way you wish to describe the dish, here it is.
Posted specifically for Ben Haslehurst, appeasing his love of mackerel, here we present the dish. I have fond memories of this dish form last year, It is ideally a pleasant lunchtime dish (as availability of rhubarb is somewhat scarce during some periods of the year, have a look around before buying fresh rhubarb - it can be expensive if imported). That said, due to its growing in greenhouses commercially, you can probably get it at any time, especially in a can. You are aware of course, i'm not fond of the idea of using rhubarb from a can. Yet when needs must...
1 large mackerel fillet (raw), bones removed.
Salt & Pepper
Rhubarb & Ginger Compote (see recipe)
Raspberry Balsamic Vinaigrette (see recipe)
Cut the sour-dough roll in half horizontally. Dress the rocket in a mixing bowl with the truffle oil and leave to sit whilst you are busy with the next bit.
In a frying pan add the butter and bring up to temperature (enough for the butter to melt). Season the butter with the salt & pepper, & when butter begins to brown (only begins, mind) turn pan down to simmer. Here we are simulating the butter to look like "buerre noisette". Add the mackerel to the pan and allow to sit there sizzling away for about 2 minutes. It wont be far off cooked already, & if you wish, put a lid on the pan (ensures the fish stays moist).
Toast the sour-dough roll, either in a toaster or under a grill. keep your eye on it though.
When you have added your fish to the pan, and are letting it simmer turn your attention to the rhubarb & ginger compote. Add it to the pan with the mackerel, and when heated through, remove from the pan and place on top of the toasted sour-dough roll, then the mackerel on top of this.
Garnish the open sandwich with the dressed rocket on top (see picture), and drizzle balsamic vinaigrette either over the salad or around the outside.