Preheat the oven to 400°F (200°C).
In a large skillet, melt the butter over medium heat. Add the flour and whisk for about 1 minute until smooth.
Gradually add the heavy cream and broth, whisking continuously until the mixture thickens, about 3-5 minutes.
Stir in the seafood mix, frozen mixed vegetables, garlic powder, onion powder, Old Bay seasoning, salt, and pepper. Cook for an additional 2-3 minutes until heated through.
Pour the seafood mixture into a greased 9-inch pie dish or oven-safe skillet.
In a separate bowl, prepare the cheddar bay biscuit mix according to package instructions, adding the milk. Stir until just combined.
Drop spoonfuls of the biscuit mixture over the seafood filling, covering it as evenly as possible.
Bake in the preheated oven for 20-25 minutes, or until the biscuits are golden brown and cooked through.
Let cool for 5 minutes before serving.