In a large mixing bowl, crack the large egg and add mayonnaise, Dijon mustard, Worcestershire sauce, Old Bay seasoning, and minced celery. Mix these ingredients thoroughly using a fork until they form a creamy blend.

Gently fold in the fresh lump crab meat and panko breadcrumbs into the mixture. Be careful not to over-mix.

Cover the bowl with plastic wrap and refrigerate the crab cake mixture for at least 1 hour.

Once chilled, lightly grease your hands and form the mixture into six large patties, about 1 inch thick.

Heat a skillet over medium heat and melt enough butter to coat the bottom generously.

Carefully place the patties in the hot skillet, cooking them for 3-5 minutes on each side.

Once golden brown, transfer the crab cakes to a plate lined with paper towels to drain any excess oil.