- 800-900g kohlrabi
- 2 smoked mackerel fillets (150g)
- 200g spinach (large leafed)
- 300ml double cream
- 100ml whole milk
- Juice of ½ lemon
- 4 tsp wholegrain mustard
- White pepper
Pre-heat the oven to 220C. Dig out a medium-sized gratin or oven-proof dish – I use a 23cm circular pan, which is about 7cm deep.
Cut any stalks off the kohlrabi and reserve the leaves. Peel with a vegetable peeler, then use a mandolin to slice into 3mm-thick pieces. Put to one side.
Wash the spinach thoroughly, remove and discard the stalks and chop the leaves in half. Put the cream, milk, 1 tsp mustard and a good pinch each of salt and white pepper in a milk pan and warm to a gentle simmer while you assemble the gratin.
Spread the kohlrabi slices in one layer. Smear with 1 tsp mustard. Season with salt and pepper and flake one third of the mackerel over the top. Place a layer of spinach (and the kohlrabi leaves if you have them) over this, then repeat three times, and finish with a fourth and final layer of kohlrabi slices.
Squeeze the lemon juice into the milk pan, then pour this over the kohlrabi. Place on a baking tray (in case the cream bubbles over) and cook in the middle of the oven for 45-50 mins, until the kohlrabi and leaves have released their juices and become tender. The cream should be bubbling round the sides and brown on top.
This makes a lovely supper, served with a crisp, refreshing salad and perhaps some fresh bread to mop up the juices.
Image: Ed Smith
If you can’t make it to the Market, Borough Market Online offers a wide selection of our traders’ produce, delivered direct to London addresses and, where available, by post to the rest of the UK. The service also includes a range of Best of Borough Market hampers and meal boxes.