Preheat the oven to 400F.
Sprinkle the salmon fillets on both sides with the salt and pepper. Spread the mustard on both sides of each fillet, dredge them in the herb mixture, and pack the herbs into the fillets with your hands.
Heat a large ovenproof skillet over high heat until very hot. Place the salmon fillets in the skillet and sear them on the first side, for about 1 1/2 minutes. Flip the fillets over and remove the skillet from the heat.
Add the water carefully around the fillets, place the skillet in the oven, and bake until the fish is medium rare, for about 6 minutes.
Makes 4 main-course servings.