Celeriac Potato Gratin

|Bring celeriac and potato together in this warming and hearty dish that will round out any good supper.|arran victory potatoes baking potatoes celariac charlotte potatoes maris piper potatoes potatoes rudolph potatoes|1 head of celeriac approximately 350g raw prepared weight3 medium potatoes approximately 350g raw prepared weight1 clove of garlic crushed with the back of your hand2 shallots500ml double cream100ml vegetable stockSalt and Freshly ground black pepperSprig of thyme + 1tsp finely chopped thyme leavesOne bay leaf30g butter|Preheat the oven to 150°C and grease an oven dish. This recipe uses a 2lb loaf tin lined with parchment paper however you can use a shallower and wider dish please remember to adjust the cooking time accordingly the cooking times for this recipe is for making the gratin in a loaf tin.Pour the cream stock bay leaf garlic sprig of thyme and seasoning into a medium saucepan. Bring tot he boil and simmer for 5 minutes. Turn the heat off and leave the cream to infuse for 20 minutes.Peel the shallots and slice into rings. Heat a non-stick frying pan with the butter and saute the shallots until golden add seasoning and the chopped thyme.Peel the celeriac and potatoes cut the celeriac into quarters. Using a sharp mandolin slice the celeriac and potatoes 2mm thick.Season the sliced celeriac and potato generously with salt and freshly cracked black pepperBring the cream back to the boil and the infused cream through a fine sieve directly over the sliced potatoes and celeriac.Start layering your gratin first pour on a bit of cream then layer the celeriac then a thin layer of the sauteed shallots then potatoes then cream and continue until all the ingredients are used. At this stage give it a good press with your hands.Let the gratin sit for 30 minutes before cooking.Bake the gratin for 2 hours (this timing is for a deep gratin in a loaf tin). If you're make a flatter version then the cooking time should be at least 30 - 40 minutes less. Test if the potatoes and celeriac are cooked by inserting a metal skewer if it glides in and out with ease it's cooked if it feels a bit crunchy return to the oven and cook longer. Do not be tempted to turn the heat up before the gratin is cooked as a high heat will curdle the cream and your potatoes will be raw not good!Let the gratin rest and before you are ready to serve place the gratin in a preheated oven at 200°C for 20 - 25 minutes to heat through and brown.|30.00 minutes|8|British Larder