Start this recipe by pouring 150ml boiling water over the tabbouleh, mix well and cover. Allow to sit for 5 minutes. Meanwhile, place the cucumber slices onto kitchen paper to remove any excess water. Cat a large piece of cling film and lay on your worktop. Lay the cucumber slices on, side by side overlapping to create a sheet of cucumber. Next, mix together the cream cheese, dill and lemon zest and spread carefully over the cucumber. Top with a layer of smoked salmon and sliced avocado. Spoon over the tabbouleh and finish off with the mixed salad leaves. Roll up tightly using the cling film and allow to set in the fridge for 1 hour. When ready, unwrap and cut into thick slices.