Tartiflette with Milk-Poached Potatoes, Caramelised Onions and Walnut Salad

Method

1. Peel the potatoes and slice them 4 mm thick; if you use a mandoline, always use the hand guard. Don't rinse them: their starch thickens the sauce. Put the potatoes, milk, cream, smashed garlic, thyme, nutmeg and salt in a wide 20 cm pan. Bring to a gentle simmer on medium heat, then turn down to medium-low heat and cook for 14 min. Milk catches easily, so stir gently from the bottom with a spatula, and stop when the potatoes are tender but still hold their shape.

   Add in this stepWaxy potatoes 500 gMilk 350 mlDouble (heavy) cream 100 mlGarlic cloves, smashed 1Thyme sprigs 2Ground nutmeg 1 pinchSalt ½ tsp

   medium heat→medium-low heat

2. Fry the lardons in a large frying pan over medium heat for 6 min, until crisp and their fat has run, then lift them out. Add most of the butter and the thinly sliced onions to the fat, turn down to medium-low heat and cook for 20 min, stirring now and then, until deep golden brown and sweet. If the bottom starts to catch, add a spoonful of water and scrape.

   Add in this stepSmoked bacon lardons 120 gButter 14 gOnions 1

   medium heat→medium-low heat

3. Pour in the wine, turn up to medium-high heat and scrape the pan as it reduces to a syrup, about 2 min. Stir the lardons back in.

   Add in this stepDry white wine 60 ml

   medium-high heat

4. Preheat the oven to 220 °C. Pick the thyme stems and garlic out of the potatoes and gently fold in the onion mixture and pepper. Butter a gratin dish with the remaining butter, choosing one that holds the potatoes about 4 cm deep, spread them in and spoon the crème fraîche evenly over the top.

   Add in this stepButter 6 gBlack pepper to tasteCrème fraîche 2 tbsp

   oven

5. Scrape the Reblochon rind lightly with a knife (don't remove it), cut it in half horizontally and lay it rind side up over the top. Bake in the oven for 18 min, until the cheese has melted, is bubbling and turning golden. Let it rest 5 minutes before serving: molten cheese is extremely hot.

   Add in this stepReblochon cheese 225 g

   oven

6. While it bakes, toast the walnuts in a dry pan over medium-low heat for 3 min, shaking, until fragrant, then chop roughly. Whisk the mustard and vinegar in a bowl, then whisk in the oil a little at a time. Just before serving, toss the leaves and walnuts in the dressing and serve alongside the tartiflette.

   Add in this stepWalnuts 20 gDijon mustard ½ tspRed wine vinegar 2 tspExtra-virgin olive oil (or walnut oil) 1½ tbspSalad leaves (frisée, romaine or similar) 80 g

   medium-low heat