Tinga comes from the Nahuatl word "tingatl," meaning something shredded, messy, or all mixed up -- basically a delicious stewed guisado of shredded meat (chicken, pork, or beef) cooked with tomatoes, onions, and chipotle chiles. While tinga originated in the Mexican state of Puebla, it's now a beloved classic all over the country, with every region adding its own twist. Salmon works beautifully here because it roasts gently in a hot oven in mere…