Boil the poaching ingredients in a large pan, remove from heat, cover, and cook the salmon in residual heat for 5 minutes.
Discard the salmon skin, flake the meat into pieces, and set aside.
Wilt spinach with water, nutmeg, lemon, salt, and pepper in a pan for 2 minutes.
Drain the spinach and stir in the pre-cooked potato.
Whisk the dressing ingredients and pour over the spinach and potato mixture.
Sauté onion and red pepper in oil until softened.
Add milk and garlic, boil for 6 minutes, cool slightly, and blend until smooth.
Plating the salad by topping vegetables with salmon and drizzling with red pepper coulis.