Sprinkle The Celery And Green Onions Into The Bottom Of A Slow Cooker; Place The Turkey Chunks On Top. Combine The Pineapple Juice, Sweet Chile Sauce, Vinegar, Water, Beef Bouillon, And Garlic Powder; Pour Over The Turkey. Place The Pineapple Rings On The Turkey Chunks. Cook On Low Until The Turkey Pulls Apart Easily, 6 To 7 Hours. Meanwhile, Make The Coleslaw By Stirring The Mayonnaise, Lemon Juice, Parsley, And Onion Together In A Mixing Bowl. Add The Cabbage And Cheddar Cheese; Season To Taste With Salt And Pepper. Cover, And Refrigerate While The Turkey Cooks. Once The Turkey Is Tender, Shred Using Two Forks. Pile Some Of The Shredded Turkey And A Pineapple Ring Onto A Kaiser Roll; Top With Coleslaw To Serve.