Open the peppers up and place skin side down in a hot, dry skillet. Press down with a spatula, you will hear a loud cracking and popping sound from the peppers skin. Once done popping, turn and repeat on the other side. This side will not make a sound. Cook until thoroughly blistered and toasted, about one minute or two.
Then add the peppers along with all adobo ingredients into a food processor and blend well. Add salt and olive oil as needed.
Slice the skirt steak against the grain into thin pieces. Toss well in the adobo marinade and allow to sit for 30 minutes. Do not refrigerate, as it is better to cook a steak at room temperature.
Blister the skins of the tomatillos or green tomatoes in the same way that you did the peppers. Once blistered and hot, add to the blender and blend all salsa verde ingredients together. Since there are so many fresh ingredients, a lot of variation can occur. Season with salt, olive oil and / or lime until there is a bold yet balanced flavor.
On high heat in either a skillet or on a griddle / plancha, cook the steak pieces over a teaspoon of olive oil. You want to char in a few places on the meat without totally overcooking it, so high heat is better.
Heat the tortillas, and add the steak, chopped white onion and fresh cilantro into each taco. Serve with the salsa verde and lime wedges on the side.