Brush edges with water and bring corners together to enclose mushroom completely and seal. Place seam side down on baking sheet. Bake for 15 to 20 minutes, or until puffed and golden. Thaw shrimp if frozen. Drain tomatoes, reserving 6 tablespoons oil.
Sliver tomatoes and set aside.
In a saucepan, heat reserved oil over medium high heat. Add garlic and shrimp. Cook for 2 to 4 minutes or until shrimp turn pink. Lift out with a slotted spoon and set aside. Add cream, broth, vermouth, basil, chives, salt, lemon peel, pepper and tomatoes to saucepan.