Deseed all the chiles and remove stems. Boil in water for 15 minutes. Place all the ingredients in a blender except 1/2 of the onion(s), the extra pineapple, the cilantro, tortillas and the meat. Liquify for 2 minutes.
Strain out the pulp from the marinade. Marinate the meat slices refrigerate for 12 hours or overnight. Be sure to cover all the meat with the marinade.
Using a large cast iron pan, fry the meat but do not burn it. If using thin steaks brown each one being careful not to leave any burned chile in the pan, remove each slice when it is browned and set aside.
Chop up all meat into small pieces. Clean the pan again to remove excess burned stuff and grease. Saute the other half of the onions (it should be coated with the adobo) and then add the chopped meat and heat again.
Prepare the tacos with corn or flour (gringa style) tortillas. Add a small slice of additional chopped pineapple if desired.
For quesadillas, add Mexican cheeses and pan toast to a golden brown.
Serve with Salsa a la Diabla, chopped cilantro, fresh lime and a chopped pineapple.