Crustacean Creation: Experience has taught me that whenever a restaurant lends its name to a dish, it's probably the best thing on the menu. The Shrimp Crostini appetizer ($9.95) at Crostini [2411 South Shepherd (713)524-8558) further confirms the theory. It's an architectural masterpiece. The base is polenta, crusty on the outside, but soft and creamy on the inside. Resting on top of this polenta are large, crispy shrimp stuffed with crabmeat; and on top of those plump, half-moon crustaceans is a meaty slice of portobello mushroom, melted mozzarella covering its dark brown surface. The whole sits in a sweet, spicy jalapeño marmalade. An order consists of four of these little darlin's, more than enough for sharing -- not that you'll ever see me passing my plate.