1. Peel cucumber. Cut cucumber lengthwise in half. Using spoon, scoop out seeds from each cucumber half. Coarsely shred enough cucumber to make 1 cup. Slice any remaining cucumber to use as garnish.

2. In medium-sized bowl, combine shredded cucumber, ground beef, bread crumbs, grated onion, salt, pepper, and egg. Divide meat mixture into 4 portions.

3. Unwrap 4 cheese slices; fold each into 1 1/2x3/4x1/2" chunk.

4. Shape each portion of meat around 1 chunk of cheese, making four 4x2" oval loaves. Arrange loaves in 12x8" baking dish; cover dish with waxed paper. Cook at medium high (70% power) 9 minutes. Remove waxed paper rotating dish a half turn; top each loaf with a slice of cheese. Cook at medium high 2 minutes longer. Let meat loaves stand 3 minutes. Remove from baking dish and arrange on warm plate. Garnish with cucumber slices.