For the Potato and porcini Puree; Melt butter in a saucepan over medium heat. Add eschalots and cook until they begin to turn translucent. Add garlic and continue to cook over a low heat until the eschallots start to caramelize and turn brown. Add potato, dried porcini and chicken stock and bring up to simmer. Simmer gently until the potato is tender. Strain through a sieve, reserving all the liquid. Place the potato mix aside and return the liquid to the saucepan, add the cream and reduce until the liquid reaches a third of its original volume. Place the cooked potato mix in a blender with the grated parmesan, and blend gradually adding the reduced stock and cream to make a puree.
For the Sautéed Mushrooms; Heat the olive oil in a large frying pan, until hot. Add in the mushrooms and thyme and cook until the mushrooms are tender and nicely coloured. It is important that your pan is hot enough and not overcrowded, or your mushrooms will stew rather than colour. Season with sea salt and cracked pepper and squeeze over the lemon juice.
For the Poached Egg; Bring a medium sized saucepan to the simmer, add 50ml while vinegar. Your water should be just bubbling, but not boiling as this will break apart you egg. Gently stir the water, then crack your egg in the centre, the movement of the water should cause the egg white to wrap around the yolk and leave you with a nice shape. Simmer the egg for 5-6 minutes then carefully remove from the water with a slotted spoon.
For the Rocket, Pine nut and Parmesan Salad;. Once pine nuts are toasted, set aside to cool slightly and lightly crush in a mortar and pestle, or roughly chop. Toss the rocket with the pine nuts and parmesan. Drizzle with olive oil and balsamic and season well. Note. Do not dress the salad until you are nearly ready to serve or it will begin to wilt the rocket.
To Assemble; Toast the sliced brioche on one side and place toasted side down on a metal tray. Spread a generous layer of the potato and porcini puree over the un-toasted side of the brioche. Place under a grill until a light golden colour. Place the brioche on a plate and top with the sautéed mushrooms, then the poached egg and top with the rocket salad. Serve.