Serve this salsa with our Chicken Enchiladas.
Place the chicken stock in a small saucepan, and bring to a boil. Reduce to a simmer, and cook until reduced to 1 cup; set aside. Place poblanos directly on a gas-stove burner over high heat or on a grill. Just as each section turns puffy and black, turn peppers with tongs to prevent overcooking. (If you don't have a gas stove, place peppers on a bakingpan, and broil in oven, turning as each side becomes charred.) Transfer to a large bowl; cover with plastic wrap. Let sweat until cool enough to handle, about 15 minutes. Transfer peppers to a work surface. Peel off blackened skin; discard. Halve peppers; discard seeds. Roughly chop; set aside.
Roughly chop tomatoes, and set aside. Roughly chop tomatillos, and add to the tomatoes, tossing to combine. Place half of the tomato mixture in a food processor, and pulse until finely chopped. Set aside remaining tomato mixture.
Heat olive oil in a large skillet; add scallions and garlic. Saute until translucent, about 5 minutes. Add processed tomato mixture and reduced stock. Bring to a simmer; add roasted poblanos, oregano, cumin, and salt. Simmer until sauce has thickened slightly, about 15 minutes. Stir in remaining tomato mixture; cook until just softened, about 2 minutes. Serve immediately, or refrigerate up to 3 days.