Preheat the oven to 190°C. Line a rimmed baking sheet with aluminum foil.
Mix together the mustard, 1 tablespoon of the coriander, the mayonnaise and maple syrup in a bowl. Put the salmon fillets on the baking sheet and sprinkle with 1/4 teaspoon each salt and pepper. Spread some of the mustard mixture evenly over each fillet.
Bake until just cooked through, 10 to 12 minute. Sprinkle with the remaining 1 tablespoon coriander and serve.