Char poblano peppers on an open flame or in the broiler. Cool, peel, seed and chop.

Heat olive oil, 2 turns of the pan, in large cast-iron skillet, add tomatillos, onions, garlic, bay, oregano, salt and pepper, soften 5 minutes. Add vinegar, sugar, Worcestershire, tomatoes and chipotle in adobo, then combine with chicken and moisten with stock and lime juice. 

Preheat broiler and place rack in middle of oven. 

Line a large baking sheet with a sheet of parchment paper and top with tortilla chips. Top with half of each shredded cheese and place under the broiler. Lightly toast the chips and melt the cheese. Remove from oven and top with chicken and remaining cheeses, then broil until cheese is brown and bubbly, about 2-5 minutes. Top the nachos with scallions, cilantro, pickled jalapeño peppers and drizzle with Mexican crema or sour cream.