The first mention of Tinga came in 1881, when dish was prepared by stewing the viscera and the blood of the pork with chipotle chile, onion and tomato, and eaten with fresh cheese and avocado. My version is mercifully less authentic. There are as many recipe variations for Tinga as there are cooks in Mexico. I've added a couple warm spice elements to the sauce but if you have nothing more than tomatoes (canned are fine!), chipotles (also canned) and onion, you will achieve tasty Tinga.