For the poached salmon, place all the poached salmon ingredients into a large pan and bring to the boil. Remove from the heat, cover and leave to cook in the residual heat for five minutes, or until the salmon is cooked through. Remove the salmon from the liquid and pull away and discard the skin. Flake the salmon into pieces and set aside.
For the spinach and potato, place the spinach into a pan, add the water, nutmeg, lemon juice and zest, salt and freshly ground black pepper and leave to wilt for 1-2 minutes. Drain off the excess water and stir in the cooked potato.
For the salad dressing, whisk all the ingredients together and then pour over the spinach and potato mix.
For the red pepper coulis, heat the olive oil in a saucepan, add the onion and red pepper and fry over a gentle heat until softened. Add the milk, garlic, salt and freshly ground black pepper and boil for six minutes, or until the red pepper is tender. Allow to cool slightly, then pour into a blender and blend until smooth.
To serve, spoon the spinach and potato onto a serving plate. Top with the flaked salmon and spoon around the red pepper coulis.