Place a pot of water on medium-high heat with the white wine, bay leaf, salt and pepper. Once brought to the boil turn the heat to low, place the salmon fillet in the liquid and simmer very gently for 6-8 minutes. Remove fish from the cooking liquid and place on some paper towelling. Allow to cool completely.
Finely flake the poached fish into a large bowl. Finely dice four of the smoked salmon slices and add to the bowl. Add the remaining ingredients and season to taste. Place in the fridge for 15 minutes so the mixture firms up slightly. Remove from the fridge and place the salmon mixture in a piping bag.
Making each roulade, one at a time, place a large piece of cling wrap on a flat surface. Lay two slices of smoked salmon next to each other on the cling wrap, over lapping slightly. Pipe lengthways onto the smoked salmon the mixture. Gently fold over the bottom end of the smoked salmon to initially seal. Roll the salmon tightly into a sausage shape and tie a knot at each end of the cling wrap. Repeat the process for the rest of the mixture.
Leave in fridge until ready to use. Remove the roulade from the cling wrap and cut into four batons.
