This wonderful, French classic has always been made with Norwegian stockfish. Some versions of the dish are made with nothing but stockfish and milk. I add baked potatoes and olive oil in this ultra rich version.
I was very anxious when I served my Brandade to a group of Frenchmen, but they either liked it or they were extraordinarily polite, because I saw several of them help themselves a second and third time.
24 hours in advance: Cut the fish in approximately 2×4 inch (5×10 cm) pieces, place in a large bowl and cover with cold water. Change water at least once. (The more frequently you change water, the more salt is removed.)
Bring water to the boil in a large pot. Strain the reconstituted fish. Boil the fish for 15 minutes until it flakes when poked with a fork. Strain. Using a potato ricer, press the potatoes into the pot. (Alternatively, push them through a sieve using the backside of a large spoon. Do not use a food mill or blender, as this will turn the mash rubbery.) Add the milk. Using a large spatula, mix until it is blended, but still retains texture. Add garlic and stir in the olive oil.
Serve on slices of baguette. Garnish with olives, parsley, and drizzle with olive oil (optional).