Heat a dry cast iron skillet (or ungreased skillet) over medium-low heat until a drop of water sizzles on contact. Place the tomato and jalapeno
in the pan and cook turning frequently, until the skins are blistered all over, about 15 minutes. Remove the tomato into a mixing bowl to catch the juices. Place the chile in a paper bag and let rest for 10 minutes.
When the chile
is cool enough to handle, peel
of the charred skin. Place the tomato, onion, garlic, cilantro, and chile in a blender
, or food processor
, and process until smooth, about 1 minute, set aside.
Pour the oil into a dutch oven
or medium saucepan
over medium-high heat until it ripples, add the pasta and cook, stirring constantly, until golden. Remove all but 2 tablespoons of oil, add the pureed tomato and chile mixture, and cook for 2 minutes, stirring continually. Add the chicken stock
and bring to a simmer
. Cover and cook for 20 minutes, or until the liquid is absorbed. Serve with shredded cheese