Scrub and cut potatoes into finger-size chips and soak in hot water for 10 minutes.
Place potatoes in a large saucepan, cover with cold water and simmer over a medium heat for 25 minutes, or until just soft enough to pierce with a fork. Carefully strain and place on a tray until they stop steaming. Place the tray of cooled potatoes in the freezer for at least 1 hour to remove moisture and enhance crispiness.
Use a sharp knife to halve the lobster from head to tail; use the tip to cut through the head and then turn the lobster around and cut through its tail. Remove the stomach sack behind the head, and the digestive tract by the tail. Wash the lobster under cold running water to clean.
Preheat oven to 220C. Take your chips from the freezer, toss in oil, season with salt and place on a lined baking tray. Bake for 40-45 minutes until golden and crisp.
Fill a saucepan with warm water and bring to a simmer on the lowest heat.
Melt the butter in the microwave and cool slightly. In a heat-proof bowl, add the egg yolks and a couple of teaspoons of water and place over the pan of simmering water. Keep heat low or the eggs will scramble. Whisk continuously for 1 minute and add vinegar. Continue whisking while slowly drizzling in the melted butter until fully incorporated. The result should be a beautiful thick sauce. Fold in your yuzu zest, juice and a little pinch of salt.
Heat an ovenproof pan on the stove, add a tablespoon of grapeseed oil and place the lobster flesh side down until it begins to sizzle. Place the pan in the oven for 8 minutes until the lobster is cooked through.
Place the lobster on a plate, spoon over yuzu hollandaise and add a handful of chips.
Serve with a simple rocket or watercress salad.