After you taste this you will never go to another so-called "authentic Mexican restaurant" again!! Note, the prep time does not include cooking the shredded meat which can be done a day or more ahead.
03To the chiles add the tomatoes, chopped onion, garlic, bullion, and salt blend until smooth.
04Add puree to onions and cook about 5 minutes.
05Add shredded meat (to make the shredded meat I boil a chuck roast, or pork roast for several hours in salted water until very tender and then shred-the chicken I just boil until cooked through and no longer pink, if cooked too long it will become mushy) stir entire mixture and cook until warmed through 1-2 minutes.
06To eat take a tostada and spread with sour cream.
07Sprinkle on some parmesan cheese if desired.
08Add shredded lettuce and top with tinga mixture.