Celeriac and prune dauphinoise | Sainsbury`s Magazine

Ingredients

• 1 x 250g pack of prunes
• 1kg celeriac, peeled (about 800g peeled weight)
• 1 x 300ml carton double cream
• 500ml milk
• 2 tbsp milk, for mixing
• 1 tbsp cornflour
• 1 tbsp chopped tarragon
• ¼ tsp grated nutmeg
• about 25g soft butter, for greasing
• 3 garlic cloves, finely chopped