To make the salsa: Preheat the boiler. Put the tomatoes on a baking sheet and broil, until the tomatoes are nice and charred, 10 to 12 minutes.
Take the tomatoes out, let them cool just until you can handle them, slip off the skins, and cut out the tough cores. Transfer the tomatoes to a big bowl (don’t you dare forget the tomato juice that has leaked out and reduced to awesomeness on the baking sheet), then roughly chop them.
While the tomatoes are broiling, heat a dry skillet over medium heat and toast the chiles (in batches, if necessary), flipping them over occasionally, until they just begin to smoke, about 5 minutes. Set them aside in a bowl.
Put the olive oil, onion, and garlic in a saucepan, set it over medium heat, and cook, stirring occasionally, until the onion is soft, about 7 minutes. Add the toasted chiles, tomatoes and 2 cups of water, bring to a simmer and cook for another 12 minutes, so the flavors come together. Let it cool a bit.
Carefully transfer the mixture to a blender. Add the cilantro, salt and pepper and puree until the mixture is very smooth.
Pour the mixture through a medium-mesh sieve into a bowl. Serve at room temperature or slightly chilled.
Store the salsa in the refrigerator, tightly covered, for up to a week, or in the freezer for a month.
Heat the oil in a Dutch oven or medium pot over medium-high heat until it ripples. Add the pasta and cook, stirring constantly, until the pasta is golden, about 3 minutes.
Scoop out and discard 2 tablespoons of the oil. Add the Roasted Tomato-Chile de Árbol Salsa and cook for 2 minutes, stirring the whole time. Pour in the chicken stock and let the liquid come to a simmer. Cover the pot and cook, stirring once in a while, until the liquid is absorbed and the pasta is tender, about 20 minutes.
Divide the pasta between two bowls and garnish with the cilantro and cheese.