Combine first 7 ingredients in a large zip-top plastic bag. Seal and marinate in refrigerator 4 to 24 hours, turning bag occasionally. Remove pork from bag, reserving marinade.
Cook bacon pieces in a large Dutch oven over medium-high heat until bacon is crisp. Remove the bacon from pan, reserving bacon drippings in pan, and set bacon aside. Add half of pork to bacon drippings in pan; sauté 5 minutes, and remove pork from pan. Repeat procedure with remaining pork. Add sliced onion and leek to pan, and sauté for 5 minutes. Add the reserved marinade, pork, sweet potato, water, and broth; bring to a boil. Reduce heat, and simmer for 10 minutes. Stir in cooked bacon and spinach, and cook for 1 minute. Place pasta into each of 6 large bowls, and top with broth mixture, cheese, and green onions.