Rainbow Seafood Pie

Working with one variety of potatoes at a time, peel, cut into three or four, place into a saucepan and cover in cold water. Place on the stove on low to medium heat and bring to a boil. Simmer until tender. Drain, air dry and place back into the saucepan for mashing. Mash it with a potato masher, or you can also put it through a ricer. Once well mashed, change to a fork and work in 10 g butter, then 10 ml milk to form a smooth, creamy mash. There must be no lumps, as these will block the nozzle when piping.

Spoon the mashed potato into a piping bag with a star or flower nozzle. Follow the same process of making mashed potato and placing it into a piping bag until all varieties of potatoes are in separate piping bags.

While the potatoes are cooking, make the white sauce. Melt the butter in a saucepan with the flour and cook gently until a nut-brown paste has formed. Turn off the heat and add the milk a little at a time, stirring well after each addition. The mix will seize after each addition, then, with more milk, gradually become looser. Once all the milk has been used, sprinkle in 1 tsp stock powder and continue diluting the mix with water until it becomes a liquid consistency. You may not need the full half cup of water, or you may require a little bit more. Turn the heat back on and stir while the mixture is heating. Add 1 tsp dry mustard powder and stir as the mixture thickens. Once the mixture has thickened and is starting to bubble, add the vinegar, stir through and add the Dijon mustard and truffle mustard. Stir through and turn off the heat. Leave to the side while finishing the mashed potatoes.

Grease a baking dish. Stir the white sauce and add the seafood, mixing well. Spoon the seafood and sauce mix into the baking dish. Pipe a line of mashed potato with the first colour over the sauce following the edge of the baking dish. Pipe another line of mashed potato, using a different colour, next to this. Continue piping the mashed potato in alternate colours until the pie is covered. 

Place in a 180-degree oven for 20 minutes or until the mash is browned and the sauce simmering. Let stand for a couple of minutes before serving.