In a saucepan over medium heat, melt butter. Add garlic, onion, & celery. Cook until soft, about 5 minutes. Stir in flour & cook 1 minute, forming a roux.
Slowly whisk in seafood broth & cream. Stir until smooth & slightly thickened, 5–7 minutes. Season with Old Bay, salt & pepper.
Add shrimp & cook 2–3 minutes until pink. Stir in lobster parsley. Remove from heat.
Biscuits
In a bowl, whisk together flour, baking powder, garlic powder & salt. Cut in the grated cold butter until crumbly. Stir in cheddar & herbs. Add milk & mix until just combined. The dough will be sticky.
Assembly
Spoon seafood mixture into 4-12 oz. ramekins or a baking dish. Drop biscuit dough over the top, spreading gently. Bake 20–25 minutes, until biscuits are golden & cooked through. Let rest 5–10 minutes before serving.