Pan-fried mackerel, rhubarb sauce, pickled rhubarb, mustard vinaigrette

To begin, make the pickled rhubarb. Place the water, sugar, white wine vinegar, lemon juice, vanilla and salt in a pan and bring to the boil, stirring until the sugar has dissolved. Add the rhubarb and cover with a cartouche, reducing to a simmer

As soon as the rhubarb is barely cooked and still firm, remove from the heat and allow to cool in the pickling liquid – ideally for 12 hours but less if you’re short on time

For the rhubarb sauce, melt the butter in a pan over a low to medium heat. Add the sugar and vanilla paste and slowly cook until the rhubarb is completely soft, most of the moisture has evaporated from the pan and the mixture is thick. Blend in a high-powered blender, pass through a fine strainer and set aside

Let the sauce down with a dash of the rhubarb pickling liquor and add some white wine vinegar to taste. Season with salt and pepper

To cook the fish, brush the flesh of the mackerel with English mustard using a pastry brush or the back of a spoon, and season with salt and pepper. Heat some olive oil in a non-stick pan and add the fillets skin-side down, pressing down evenly for 30 seconds with a spatula to ensure an even colour

Leave to cook on this side for 2–3 minutes depending on the thickness of the fillets, then turn the fish over and remove from the heat. It will finish cooking in the residual heat of the pan

To make the vinaigrette, place the mustard in a bowl, whisk in the white wine and water, then drizzle in the olive oil. Season with salt and pepper and emulsify using a hand blender or whisk

To serve, dress the salad leaves with a little vinaigrette and squeeze some fresh lemon juice over the mackerel. Place some of the rhubarb sauce on the plate and top with some pickled rhubarb and a mackerel fillet. Garnish with salad leaves and some of the mustard vinaigrette