Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish or oven-safe skillet.

In a skillet, melt butter over medium heat. Add shrimp and cook until pink, about 3–4 minutes. Stir in crab meat and frozen vegetables.

Sprinkle flour over the seafood mixture, stirring to coat. Slowly whisk in seafood stock, then add heavy cream. Bring to a gentle simmer and cook for 5 minutes until thickened.

Season with garlic powder, onion powder, thyme, salt, and pepper. Remove from heat.

Pour filling into the greased baking dish, spreading evenly.

In a bowl, mix Cheddar Bay biscuit mix, shredded cheddar, and milk until a soft dough forms. If too sticky, add 1 tablespoon biscuit mix at a time.

Spoon dough over the filling in small dollops, leaving slight gaps for steam to escape.

Bake for 25–30 minutes until biscuits are golden brown and cooked through.

Let cool for 10–15 minutes to set before serving.

Scoop into bowls, making sure each serving has a biscuit top.