Method

• Preheat oven to 180 degrees Finely slice the onion and finely chop the garlic
• Heat a pot on a moderate heat, add the butter and then cook the onion and the garlic until softened without colouring
• Add the tarragon
• Add the flour and continue to cook for one minute
• Whisk in the milk 1 cup at a time, allowing it to thicken each time before adding the next
• Peel and slice the potatoes about 2mm thick (I like to use a mandolin or a food processor if possible)
• Wash, quarter and remove the core from the apples (leaving the skin on is fine) and then slice the same thickness as the potatoes Place a layer of the potato in the bottom of a baking dish approx
• 20 x 30 cm
• Lightly season with salt and pepper and then add a layer of the apples
• Pour over 1/3 of the sauce and continue this process until you layered all of the potato and apple, finishing with a layer of the sauce
• Grate the cheddar and sprinkle over the top of the gratin
• Cover with foil and bake in the oven for 1 ½ hours or until the potato is tender
• Remove the foil and continue to cook for another 5-10 minutes to brown the top of the gratin Enjoy as a side dish with a main meal