Melt Butter: Begin by melting the butter in a saucepan over medium heat on your stovetop until it’s frothy but not browned.
Sauté Vegetables: Add the chopped celery and green onions to the melted butter, sautéing them until they begin to soften, releasing their fragrant aromas.
Add Flour: Stir in the flour, continuing to sauté for another minute which will help create a roux that thickens your bisque.
Incorporate Milk: Warm up whole milk in the microwave until it’s just warm to touch, then pour it into the saucepan while whisking vigorously until all lumps disappear.
Mix in Cream and Seasonings: Whisk in heavy whipping cream, tomato paste, Old Bay seasoning along with salt and pepper, stirring until everything is well combined.
Simmer and Serve: Allow the mixture to come to a low simmer before adding shrimp and crab meat; cook until heated through then serve hot garnished with fresh parsley for an extra touch of flavor.