1. Preheat oven to 400 degrees. Combine ground beef, egg, panko crumbs, spices, and pareve milk in a large bowl. Mix well until completely blended. Form into 21 golf-sized balls and set aside
2. Bring a small pot of water to a boil. Drop in pearl onions and boil for three minutes. Drain and rinse under cold water. Slice off root ends and press out onions from opposite end.
3. Place barbecue sauce ingredients in a saucepan and bring to a boil (or place all ingredients in a bowl and microwave for two minutes).
4. Slice each piece of beef fry in half and wrap around each meatball.
5. Thread a wrapped meatball on the skewer, followed by a pearl onion and then a mushroom. Repeat and end with a third wrapped meatball.
6. Brush each kebab with barbecue sauce. Bake uncovered for 10 minutes. Turn each kebab over and brush with barbecue sauce. Bake uncovered for an additional 10–15 minutes.