Combine the mayonnaise, mustard, honey, and lemon juice together in a bowl. Cover and chill in refrigerator until ready to use.
For the Salmon:
Pre-heat oven to 400 degree F.
Combine the chopped parsley,garlic, mustard, salt, olive oil and lime or lemon juice in a small bowl.
Slice salmon into even portions. Lay them onto a lined baking dish with the skin-side-down.
Generously brush all sides of salmon with the pre-pared sauce and top with fresh slices of lemon.
Bake for 12-15 min or until just cooked through and flaky. Be careful not to over-cook or it will be dry.
For the couscous:
Bring the water to a simmer in a small pot over medium heat, then turn off the heat.
In a shallow baking dish combine the couscous, salt and olive oil, tossing to coat. Add in the warm water and smooth the couscous into an even layer. Cover the dish tightly with plastic wrap and allow it to rest for 15 minutes while the salmon bakes.