Mix the rosemary, thyme and black pepper
Spray the bottom of the fish with cooking spray. Spread 1 T. mustard on top of each fillet. Sprinkle about 1-1/2 T. herbs on each.
Place herb side up on grill. Close cover and cook about 12 minutes.
NOTE: I have also done these in the oven -- 400 for about 12-15 minutes.