Preheat oven to 450 F and line a rimmed baking sheet with a silicone liner, parchment or foil.
Arrange salmon fillets on the prepared baking sheet, skin side down.
In a small bowl, add the marinade ingredients: parsley, garlic, oil, lemon juice, Dijon mustard, salt and pepper. Stir to combine.
Generously spread the marinade, brushing over the top and sides of the salmon and then top each piece with a slice of lemon.
Bake uncovered at 450 F for 12 to 15 minutes or until just cooked through, flaky and the salmon reaches an internal temperature of 145 F at the thickest portion on an instant-read thermometer. Do not overcook.