1.Season Beef Roast And Pork Loin With The Salt And Pepper. Place Seasoned Beef And Pork In A Slow Cooker. 2.Set Slow Cooker To Low. Cover, And Cook Overnight Or 8 To 10 Hours. Drain The Juices And Shred The Meat Into Strands. Return The Meat To The Slow Cooker; Pour The Enchilada Sauce And Green Chiles In With The Shredded Meat And Cook On Low Another 4 To 8 Hours.