• Start by preheating your oven to 375°F (190°C).
• While the oven heats up, make the sauce. In a medium bowl, mix the grainy mustard, Dijon mustard, honey, minced garlic, lemon juice, and olive oil.
• Lay out a piece of foil on a baking sheet. It should be big enough to wrap around the salmon. Put the salmon on top of the foil and season it with kosher salt.
• Pour the sauce over the salmon. Spread it around using a spoon or a pastry brush. Then, fold the sides of the foil over the salmon to make a sealed packet.
• Bake the salmon in the oven for about 15 to 20 minutes. If your salmon is thicker, it might take a bit longer. You'll know it's done when it's easy to flake with a fork. The inside temperature should be 145°F (63°C) if you use a thermometer (I prefer 125°F/52°C, but the FDA recommends 145°F/63°C)
• After baking, open the foil and put the salmon under the broiler for a few minutes. This will make the top nicely caramelized.
• Before serving, sprinkle the salmon with chopped parsley. It's best to serve it right away, while it's hot.

To Cook on the Grill:

• Just move the foil packet with the salmon onto the grill. Grill for about 15-20 minutes, or until the salmon is almost completely cooked.
• Open the foil and grill for another 3-4 minutes.