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Potato Gratin

Potato Gratin with Porcini Mushrooms

A great decadent side to your Christmas Roast, this Potato Gratin with Porcini Mushrooms is decadent and filling enough to stand as a main dish on its own. Creamy, with strong earthy aromas of porcini and thyme, our Potato Gratin goes very well with beef, lamb or gammon, or simply with a variety of roast or steamed vegetable sides!
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Prep Time 40 mins
Cook Time 1 hr 30 mins
Total Time 2 hrs 10 mins
Course Side Dish, Vegetarian Main
Cuisine Christmas, French
Servings 8 side dishes
Calories 296 kcal


  • Mandolin or Food Processor with Slicer Attachment
  • Blender/ Smoothie Maker
  • Ovenproof dish


  • 800 g King Edward or Maris Piper Potatoes
  • 400 ml double cream
  • 150 ml milk
  • 15 g dried porcini mushrooms
  • 1/2 tsp fresh thyme chopped
  • 1 shallots roughly chopped
  • 2 garlic cloves roughly chopped
  • 1/4 tsp nutmeg
  • 15 g butter
  • 30 g parmesan


  • Pour the milk and double cream into a large pan. Add dried porcini mushrooms, thyme, garlic, shallot, nutmeg and a tsp of salt. Bring the mixture to a gentle boil and simmer for 5 minutes. Then cover with a lid and leave to cool down for 30 minutes.
  • Pour the cooled mixture into a blender/ smoothie maker/liquidiser and blitz into a smooth liquid.
  • Peel the potatoes and using a mandolin or a food processor with a slicer sttachment, slice the potatoes into 2-3mm thick slices.
  • Preheat the oven to 140°C Fan. Grease an ovenproof dish with butter generously.
  • Layer a quarter of the potatoes to cover the bottom in an even layer. Pour a quarter of the cream mixture. Then layer another quarter of the potatoes and top with the sauce again. Carry on like this until you have no potatoes or sauce left.
  • Top the gratin with grated parmesan, a sprinkling of salt and pepper. Cover the dish with foil and pop into the oven for 1-1.5 hours. After an hour, uncover the dish and check if potatoes are cooked through and tender by inserting a sharp knife. Once cooked, increase the oven temperature to 180°C and place the uncovered dish back in the oven for another 10-15minutes.


Sodium: 108mgCalcium: 115mgVitamin C: 21mgVitamin A: 838IUSugar: 2gFiber: 3gPotassium: 532mgCholesterol: 77mgCalories: 296kcalTrans Fat: 1gMonounsaturated Fat: 6gPolyunsaturated Fat: 1gSaturated Fat: 13gFat: 22gProtein: 5gCarbohydrates: 22gIron: 1mg
Keyword Potato & Cep Gratin, Potato & Mushroom Gratin, Potato & Porcini Gratin, Potato Gratin, Potato Gratin with Ceps, Potato Gratin with Mushrooms, Potato Gratin with Porcini, Potato Side Dish Recipes
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