Cook chorizo in a saute pan over medium heat until fully cooked. Drain and crumble. Set aside.
Preheat broiler. Remove stems from poblano peppers, place in baking sheet or rack of broiler pan and broil about 2 inches from heat, turning frequently until skins are blistered and charred, about 15 minutes. Remove from oven, place in a bowl and cover with plastic wrap for 10 minutes or until cool enough to handle. Remove skin and seeds. Cut into ½-inch pieces.
Heat oil in a medium saucepan over medium heat for 5 minutes. Add poblano peppers, onion and serrano pepper and cook for 5 minutes, until onion is translucent. Add garlic and cook for 1 minute.
Pour heavy cream over onion and pepper mic and cook on medium-low heat for 3 to 5 minutes, until hot but not boiling. Reduce heat to low and stir in cheeses until smooth. Remove from heat and add chorizo. Season with salt. Top with cilantro and green onion. Serve with tortilla chips.
