Diana Henry’s beetroot and potato gratin

This is absolutely delicious with roast beef or salmon. You can add about 3 tsp of creamed horseradish if you want (just spread it out between the layers). It’s also good with the addition of flaked smoked mackerel, in which case it makes a good main.

Prep 20 mins | Cook 1 hour

6 as a side dish


1kg potatoes, preferably waxy ones
500g cooked beetroot
425ml double cream
140ml sour cream
85ml full fat milk
salt and pepper
3tsp creamed horseradish (optional)

What to do:

  1. Pre-heat the oven to 180C
  2. Peel the potatoes and slice very finely – a mandoline is the best way to do this. Cut the beetroot into fine slices as well – they don’t have to be as thin. You can cut them with a knife.
  3. In a large saucepan, mix together the creams and the milk and bring the liquid to just under the boil. Add the sliced potatoes and cook gently for 5 minutes.
  4. Season really well and spoon ½ the potatoes into a buttered gratin dish. Put a layer of beetroot on top – seasoning as you go, then top with the rest of the potatoes and their cream. Put in the oven for 1 hour, or until the vegetables are completely tender. You may need to cover the top with foil after 45 minutes to stop the top becoming too dark in colour.