I make a variety of baozi, which really isn't that different from empanadas. Here's a few to try out:

Ground pork, chives, garlic. A classic in my book

Pizza - Pepperoni, sausage, mozzarella, pizza sauce

Biscuits and gravy - Make a thick sausage gravy and let it cool down. It should become thick enough to use as a filling. When it heats up, it becomes more liquidy again. Just be careful with that hot gravy

Cheese burger - ground beef, diced onions and tomatoes, shredded cheese