Layer bottom of slow cooker with the sweet potatoes.
Add all ingredients except sweet potatoes and an optional 1/2 cup of ketchup on top in a large bowl. I like to mix mine by hand. But I make sure I remove rings and have everything in the bowl before mixing with hands, so I do not have to take them out until done mixing.
Form meat into a loaf shape and place on top of sweet potatoes
If desired, cover with ketchup. Place lid on slow cookers.
Cook on high for 5 to 6 hours or low for 7 to 8 hours.
Thirty minutes before serving, turn the slow cooker off.