Add parsley, sherry, mustard, lemon juice, salt, rosemary, sugar, pepper, garlic and shallots to a food processor and blend finely while slowly adding olive oil. Blend until marinade emulsifies.
Place striped bass fillets into a plastic bag and add the marinade. Gentle shake to coat fillets. Refrigerator for 1-2 hours, turning the bag over halfway through.
Pre-heat grill to medium-high.
Place fish on the grill and cook for about 5 minutes, basting occasionally. Flip over and repeat, cooking until done.
Contributed by Eric Herbst, Coastal Aquaculture Specialist, North Carolina Sea Grant