Puree the sauce in an electric blender or food processor and strain through a fine sieve if desired. Set aside.
To make the enchiladas, saute the chorizo and onion in a skillet over high heat, breaking up the meat, until the meat is thoroughly cooked, about 10 minutes.
2 lbs Mexican chorizo, 1/2 large onion
Stir in the potatoes and remove from the heat. Place 3 to 4 tablespoons (45-60 ml) of the filling on each tortilla and roll them tightly.
2 cups potato
Spread about 1 cup (250 ml) of the guajillo sauce in a large baking dish and place the enchiladas seam-side down in the dish.
16 in corn tortillas
Cover with about 2 cups (500 ml) of the sauce (freeze the remainder) and sprinkle with the shredded cheese.
1 cup Monterey Jack
Bake in a preheated 350F (180C) oven for 10 to 15 minutes.