For the Barley:

1. In medium saucepan with lid, bring 3 cups water to a boil. Add 1 cup whole grain barley kernels (also called hulled or hull-less barley) and return to boil.
2. Reduce heat to low, cover and cook 50-55 minutes or until barley is tender and most of liquid is absorbed. (NOTE: Whole grain barley tends to absorb less moisture than pearl barley and it may be necessary to pour off any unabsorbed liquid after cooking.)
3. Place any extra cooked barley in an airtight container and refrigerate or freeze for up to a week. Add to soups, stews, casseroles and salads for extra flavor and fiber. For best results, bring frozen or refrigerated cooked barley to room temperature before using.

For the Peppers:

1. Preheat oven to 375° F.
2. In large bowl, combine ground meat, onion, bread crumbs, Parmesan cheese, egg, salt, pepper, and cooked barley.
3. Divide meat-barley mixture into 6 portions. Press each portion into a bell pepper half, forming mixture to the shape of the pepper.
4. Spray a 9x13-inch baking dish with non-stick cooking spray. Place filled pepper halves in dish. Pour pasta sauce over peppers. Cover tightly with aluminum foil. Bake peppers for 1 hour and 15 minutes.
5. To serve, arrange peppers on platter, spooning a portion of sauce over each pepper. Pour remaining sauce from baking dish into container to serve at table. Sprinkle additional grated Parmesan cheese over peppers, if desired, and serve.