Confit Egg Yolks and Baked Potatoes with Mustard Seeds and Hazelnuts

Method

1. Confit the egg yolks: Set the sous vide or a digital immersion circulator to 65°C (149°F). Place the egg yolks in a sealable bag and cook for 2 hours.
2. Remove the outer membrane of the confit egg yolks. Mix the yolks together, and season with salt and lemon zest. Transfer the mixture into a piping bag.
3. Prepare the hazelnuts: Cut the hazelnuts in half and fry in butter until golden.
4. Prepare the pickling liquid: Combine vinegar, white wine, sugar, water, thyme, and peppercorns in a pot and bring to a boil. Once boiling, strain the mixture. Add the mustard seeds and boil for an additional 5-10 minutes. Transfer to a container and allow to cool.
5. Prepare the baked potatoes: Using a mandoline, slice the potatoes 1-2 mm thick. Cut the slices into long rectangles and tie together with kitchen string. Bake in the oven at 180°C (356°F) for about 20 minutes, adding butter, thyme, and garlic for flavor.
6. Dice any remaining potato into small cubes (brunoise) and blanch in boiling water.
7. Once the potatoes are baked, pan-fry in oil with garlic, thyme, and additional butter.
8. Prepare the blanquette sauce: Heat the cream until it’s just below the boiling point. Melt the butter in a separate pan. Blend egg yolks, creme fraiche, salt, and lemon juice using an immersion blender. Slowly pour the melted butter and then the heated cream into the egg yolk mixture.
9. Pour the blanquette sauce back into the saucepan and cook, stirring constantly, until it reaches 82°C (179.6°F).
10. Finally, incorporate finely chopped chives and sorrel into the sauce.