From The Italian Slow Cooker, by Michele Scicolone. I have not made this yet, but it seems like a natural. Because the meatballs are added halfway through, it's not a recipe for those who need to be away all day. However, I think I would freeze the meatballs, and add them at the beginning. Escarole is a wonderful leafy vegetable, not well known in the US. Spinach or Swiss chard are suitable substitutes. The original recipe did not specify, but spinach should really be added only towards the end of the entire cooking period.