In a medium mixing bowl, combine sherry, soy sauce, vegetable oil, honey, paprika, ground celery seed, red pepper flakes, black pepper, and garlic powder.

Whisk or stir until all ingredients are well combined.

Place steaks in a shallow dish or resealable plastic bag.

Pour marinade over steaks, ensuring they are evenly coated.

Cover or seal the dish/bag and refrigerate for at least 4 hours, or overnight for best results.

When ready to cook, remove steaks from the marinade and discard excess marinade.

Grill steaks to desired doneness.