Wipe fish with a damp cloth, dot with butter, and sprinkle lemon juice over all. Use either of the spice mixes shown below. Herb Mix No. 1: Prepare onions and sprinkle over the top of the fish. Combine the remaining herbs/spices and sprinkle on halibut. Let stand for 10 minutes to absorb the flavors. Bake at 350 F. for 20 minutes or until fish flakes easily with a fork. Serves 6. Herb Mix No. 2: Mix all ingredients together well. Sprinkle over fish; use only enough to lightly cover fish or it will taste dry. (The remaining mix will store well in a tightly covered jar in the refrigerator.) Bake at 350 degree F. for 20-30 minutes or until fish flakes easily with a fork. Do not overbake or it will dry out. Serve garnished with lemon wedge and parsley sprigs.