Whisk together the mustard, soy sauce, sesame oil, olive oil, honey, water, and garlic together in a small bowl.
Preheat the oven to 450 degrees. Line a baking sheet with tin foil (for easier clean-up). Coat the tin foil with cooking spray.
Lay the salmon, skin side down, on the baking sheet. Pour half of the marinade on top of the salmon making sure to spread it evenly. Reserve the remaining marinade. Season the top of the fish with freshly cracked black pepper, to taste. Let the fish sit for 10 minutes while the oven preheats.
Place into the oven and bake for 10 minutes or until the salmon flakes easily with a fork. Remove from the oven and serve with reserved marinade. Serve immediately. Enjoy.