Place bulgur in a fine strainer and rinse thoroughly with cool water.
In a food processor, finely chop the onions. Add beef, 1/2 cup water, pepper, cumin, cinnamon, and 1 teaspoon salt. Whirl until mixture is a smooth paste.
Add bulgur and 1/4 cup parsley; whirl just to mix.
Pat meat mixture evenly into a shallow 1- to 1 1/2-quart casserole. Cut through meat mixture to make diamonds 2 to 3 inches wide. Place a peppercorn in the center of each diamond.
Bake, uncovered, in a 425° oven until meat is no longer pink in center (cut to test), about 25 minutes. Sprinkle with remaining parsley and add salt to taste.
To serve, cut diamonds apart and accompany with yogurt.