Reduce 50ml vinegar with peppercorns, bay leaf, and tarragon to one tablespoon and strain.
Blend yolks with the liquid while gradually adding 110g clarified butter in a food processor.
Stir in lemon juice, mustard, and cayenne, then keep the sauce warm and covered.
Mix mashed potato, salmon, smoked salmon, crème fraîche, and dill in a large bowl.
Heat 75g butter in a frying pan until hot.
Pack mixture into a metal ring in the pan and fry for 3 minutes per side.
Bring salted water and vinegar to a simmer and create a whirlpool.
Poach eggs for 3 minutes, drain on a plate, and repeat for all eggs.
Place hash browns on plates and top with poached eggs and hollandaise sauce.