Thaw and bake pastry shells according to package directions.
Meanwhile, melt the butter in a medium saucepan. Add onion and garlic; cook and stir over medium heat for 5 minutes or until tender. Stir in flour and ground red pepper. Stir in half-and-half or light cream and wine or champagne. (Mixture may appear curdled, but will become smooth as it cooks.) Cook and stir until thickened and bubbly; cook and stir 1 minute more. Add Brie, stirring until melted. Add lobster or crabmeat; heat through.
Spoon into baked pastry shells. Garnish with peppercorns, capers, figs, or almonds as desired.