Use this recipe to make our Zarape De Pato.
Roast the peppers directly over a gas burner until slightly charred, turning frequently (alternatively, roast under the broiler). Transfer to a medium bowl, and cover with plastic wrap; let stand about 15 minutes. Use a paper towel to rub off charred skins. Remove and discard stems, seeds, and ribs. Roughly chop peppers, and set aside.
Prepare an ice bath. Bring a pot of water to a boil; blanch the spinach until bright green and wilted, about 30 seconds. Using tongs or a slotted spoon, transfer spinach to ice bath to cool. Drain, and wring spinach to remove as much liquid as possible; roughly chop.
Puree the reserved peppers, spinach, stock, and cilantro in a blender. Transfer to a medium saucepan; bring to a boil. Stir in cream and salt; cook just until sauce comes to a boil. Remove from heat. Let cool before serving or storing. Sauce can be refrigerated in an airtight container up to 3 days. Reheat gently over low heat, being careful not to boil.