Preheat your oven to 400°F (200°C).
In a saucepan over medium heat, melt butter. Add garlic, onion, and celery. Cook until soft, about 5 minutes.
Stir in flour and cook for about one minute until it forms a roux.
Slowly whisk in seafood stock and cream. Stir until smooth and slightly thickened over about 5–7 minutes.
Season with Old Bay seasoning, salt, and pepper.
Add shrimp and cook for about two to three minutes until they turn pink. Stir in lobster and parsley before removing from heat.
In a bowl, whisk together flour, baking powder, garlic powder, and salt for the biscuit topping.
Cut in the grated cold butter until crumbly.
Stir in cheddar cheese and herbs into your biscuit mixture.
Add milk gradually until just combined.
Spoon seafood mixture into ramekins or a baking dish. Drop biscuit dough over the top gently.
Bake for about 20–25 minutes until biscuits are golden brown and cooked through.