1 For the lime mayonnaise, mix the egg yolk with the mustard, salt, pepper and honey. Whisk vigorously until the mixture is a smooth consistency. Stir in the lime juice and zest, then cover and refrigerate.
2 For the salmon burgers, peel the shallot and chop very finely. Cut the salmon fillet into small pieces, then chop finely. Mix the salmon with the shallots, parsley, lemon juice, cottage cheese, egg and bread crumbs, and season with salt and pepper. With floured hands, form the salmon into 8 patties and fry in a pan with hot oil for about 4 minutes on each side, until golden brown.
3 To serve, slice the Ciabatta bread and toast the cut surfaces in hot butter until golden brown. Rinse the arugula and spin dry. Place a salmon burger and a little arugula on half the bread slices, spread some lime mayonnaise on it and cover with the other half of the bun. Serve with the remaining lime mayonnaise on the side.