1. Place meat into a large ziplock bag and add one cup pomegranate juice. Pour in two teaspoons balsamic vinegar and add brown sugar, seasonings, and sautéed onions. Seal and shake well to coat.
2. Allow to marinate for at least one hour, turning once or twice to allow meat to absorb the marinade.
3. Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).
4. Remove meat from the marinade and arrange in a single layer in a baking pan. Pour in about half the marinade; discard the rest. Cover pan tightly and bake for two hours and 15 minutes.
5. Meanwhile, boil remaining pomegranate juice in a small saucepan for about 12–15 minutes, allowing liquid to reduce and turn slightly syrupy. Remove from heat and add in remaining two teaspoons balsamic vinegar.
6. To serve, drizzle pomegranate reduction over each piece and garnish with crispy fried onions.