Sill gratin

Instructions

1. 1

   Butter an ovenproof dish of about 2L. Melt 10g butter in a large frying pan and sauté the onions on a low heat for 10 minutes, turning occasionally until soft and golden.

2. 2

   Strain the herrings. The jar contains small pieces. Cut each into fine strips to distribute them across the two layers you will create.

3. 3

   Heat the oven to 200ºC, gas mark 6. In a large saucepan that can hold all the potatoes, heat the double cream, soured cream and milk to just under the boil. Reduce the heat to low and add the potatoes, turning them over a couple of times to get them coated, then cook for 10 minutes. They should have lost their rawness but not be soft.

4. 4

   Lay a third of the potatoes and their liquid in the buttered dish, sprinkling over half the dill. Season with salt and pepper (you don’t need much salt, but you need pepper).

5. 5

   Spoon half the onions over the potatoes and lay half the herring pieces on top. Repeat the layers, then finish with the final third of the potatoes and their liquid.

6. 6

   Bake for 1 hour, then check the potatoes with a sharp knife. The potatoes should be completely tender throughout. If not, cover the top with foil to stop the dish getting too dark and return to the oven for 5-10 minutes more. Serve with a green salad or the beetroot, lentil, grape & chicory salad below.