Place chicken in saucepan, cover with water by about 2 inches. Add the salt and marjoram (or oregano) and bring to a bare simmer. (Bubbles should be coming up about two or three at a time.) Simmer for about 15 minutes or until cooked through (a fork should go in easily), turning now and then. If time allows, let cool in the liquid. Shred, either by hand or with a beater. Taste and adjust seasoning.
Line a large sheet pan with foil. Add the Poblanos (touching each other), the tomatillos, the onion, garlic, and jalapeno. Broil until poblanos are blistered and other items are slightly charred in spots, turning and removing as each item as needed. Wrap everything up in the foil and allow to steam for about 15 minutes.
Peel and pick off as much of the skin on the poblanos as possible, and remove stems. Open up and remove seeds and ribs. Do the same for the jalapeno. Remove the charred skin from the onion. Squeeze garlic out of the skins.
Add all the roasted vegetables, the poblanos, tomatillos, onion, garlic, and jalapeno to the blender with any juices. Add the cilantro if using. Add salt, cumin, and marjoram along with the chicken broth and vinegar. Blend until as smooth as possible.
Heat oil in a saucepan or pot with high sides. Add the sauce and allow to bubble, stirring often for two to three minutes until desired consistency is reached.
Preheat oven to 350 degrees F.
Mix shredded chicken with about a cup of the cheese.
Condition tortillas using one of the methods in the post above. Spray a baking pan with oil, then place about 3/4 cup of the Enchilada Sauce on the bottom. Working with a few tortillas at a time, add filling, about 1/4 cup (mentally divide it), and roll, place seam side down in pan. When finished, cover with remaining sauce.
Bake, uncovered, for about 20 minutes until heated thoroughly, sauce is bubbling and cheese is melted. Remove from oven, garnish as desired.