In a heavy-bottomed saucepan or Dutch oven, melt the unsalted butter over medium heat.

Add the minced onion and celery, cooking until softened and translucent, approximately 6 minutes.

Whisk in the flour, Old Bay seasoning, and dry mustard to create a roux, cooking for 2 minutes while stirring constantly.

Gradually stream in the whole milk and heavy cream while whisking vigorously to prevent lumps.

Bring the liquid to a light simmer and cook until thickened, about 5 to 7 minutes.

Incorporate the dry sherry and Worcestershire sauce into the base.

Gently fold in the lump crab meat, ensuring the large chunks remain intact.

Reduce heat to low and simmer for 5 minutes until the crab is heated through.

Adjust seasoning with salt and white pepper as needed.

Garnish with fresh parsley before serving.