Long ago, we realized that any vegetable or fruit slice sturdy enough to hold up under a dollop of seafood salad or a slice of pâté can replace the cracker or toast point for canapés. Consider slices of cucumber, radish, apple, pear, zucchini, cooked crisp potato, beet, and baby squash; crisp endive and radicchio leaves, yellow and red cherry tomato halves. You can even use cookie cutters and go wild with shapes. But don’t stop there. Use tender spinach or basil leaves to wrap up succulent shrimp or little fingers of poached fish. Turn snow peas or mushroom caps into little boats for a delicate creamy cheese or seafood mousse.