WHAT YOU DO
Step 1: POTATO PREPARATION. Preheat a water bath to 98C/208F. Add the potatoes to a sous vide bag along with the butter, kombu, dulse and salt, then seal. Cook in the water bath for 1 hour until the potatoes are cooked through, then cool down in an ice bath. Once chilled, remove and separate the potatoes from the kombu and cooking liquid. Set aside. Top and tail the potatoes then transfer to a new sous vide bag with the cooking liquid. Seal and leave to marinate in the fridge for 24 hours. Finely chop the cooked kombu and dulse and reserve for the beurre blanc.
Step 2: VINEGAR REDUCTION. Combine all the ingredients in a small saucepan over a medium heat and reduce by half. Pass through a sieve.
Step 3: POTATO CRISPS. Preheat the oil in a deep-fat fryer to 160C/320F. Peel the potato and slice to a thickness of 2 mm (1/16 inch) and deep-fry until golden, then drain on paper towels and season with vinegar powder and salt. Reserve in a dehydrator at 60C/140F.
Step 4: DULSE BEURRE BLANC. Reduce the vinegar reduction in a saucepan until it is a light syrup. Add the double cream, stir and let it come to the boil, then reduce the heat, add one-quarter of the diced butter and whisk gently, creating an emulsion. Repeat these last two steps until all the butter is added, then remove from the heat, add the chopped kombu and dulse, and mix. Leave to infuse for 5 minutes, then season to taste with lemon juice and salt.
Step 5: ROE MIX. Put the trout and smoked herring eggs into a bowl with the chives and mix gently.
Step 6: TO ASSEMBLE. Bring a small saucepan of water to the boil over a medium heat. Add the sous vide bag with the potatoes and simmer for 10 minutes. Open the bag and transfer the potatoes to a tray to drain. Place a potato on a plate. Cover the top of the potato with the roe mix. Add the potato crisps so they are standing upright, then place all the herbs and flowers in between the crisps. Finish by pouring the dulse beurre blanc into a sauce jug. Once ready to serve, pour the beurre blanc around the potato.
