Heat a 9-inch cast iron skillet over medium-high heat. Add in chorizo and cook, stirring occasionally until browned, about 5 minutes.
Add in onion and poblano pepper and saute until soft and chorizo is completely cooked through, about 7 to 10 minutes. Drain excess grease and moisture.
Stir in shredded cheeses and transfer the skillet to the oven, about 8 inches from the broiler. Broil on high 3 to 5 minutes, until cheese is melted, bubbling, and starting to brown.
Garnish with Roma tomatoes and cilantro. Serve hot with tortilla chips.
