Soak the cod in the milk for 24 hours to remove excess salt. Poach cod in fresh milk for 6 minutes. Cook potatoes until tender in salted water, drain and cool. In a small saucepan cook garlic and cream over medium heat until tender 8 to 10 minutes and cool. In a food processor pulse the 1/4 of the garlic, potato and cod at a time. Remove the mixture and repeat. Fold the olive oil in by hand. Adjust the seasoning. Brandade should be light and fluffy.
Slice the cucumber as thin as possible but retaining a full green ring. Sprinkle with salt and let stand an hour. Drain the cucumbers and season with vinegar and sugar. In a few minutes, once the sugar dissolves, the cucumbers are ready to serve.
Serve a heaping spoonful of Smoked Cod Brandade with your favorite melba or toast point. Garnish with pickled cucumbers, caviar and a sprig of dill.