floury potato 100g,
peeled and diced into 2cm cubes
cauliflower ½ head,
broken into florets
nutmeg for grating
pine nuts 2 tbsp
sultanas 2 tbsp
balsamic vinegar 2 tbsp
honey 2 tsp
mackerel fillets 4
dill chopped to make 1 tbsp,
plus more to serve
Put a medium-sized pan of water on to boil, crumbling in the stock cube with half of the milk. When the stock is boiling, tip in the potatoes and cauliflower and boil for 8 minutes until both are really tender.
Drain the veg over another pan or bowl to catch the cooking water. Tip the veg back into the empty pan with the remaining milk, salt, pepper and a good grating of nutmeg and mash first, before finishing with a stick blender to make a really smooth purée. You want a soft consistency, so add a splash of the cooking water if you need to.
Fry the onion in 2 tsp oil in a frying pan until soft. When it’s beginning to caramelise, stir in the pine nuts and sultanas for a minute. Add the vinegar and honey with 2 tbsp of water and simmer gently over a low heat to reduce a little.
Heat the grill to high. Brush the mackerel with 1 tsp oil on both sides and grill skin-side up for 2-3 minutes, until the skin is blistered and the fillets are cooked.
Stir the dill through the sticky onions and re-heat the cauliflower purée if you need to. Swirl the purée over two plates, sit the mackerel fillets on top and spoon over the onions with a few more dill fronds.