Sauté: In a pot, melt butter and sauté onion and garlic until soft. Add flour and cook for 1-2 minutes to make a roux.
Simmer: Gradually add stock, stirring until smooth. Bring to a simmer and cook for 10-15 minutes.
Add Seafood: Stir in crab meat, shrimp, Old Bay seasoning, salt, and pepper. Cook for another 5-7 minutes until shrimp are cooked through.
Cream: Lower heat and stir in heavy cream. Simmer for 5 minutes until thickened.
Serve: Garnish with fresh herbs if desired and serve warm
