Preheat oven to 375°F.
Remove chorizo from its casing and brown in skillet over medium-high heat. Drain chorizo on paper towel.
In heavy-bottomed saucepan, bring to boil two cups of milk, half and half and guajillo chiles. Lower heat and simmer for twenty minutes. Strain milk mixture and discard chiles.
In heat-proof bowl, whisk remaining milk with cornstarch. Carefully, add one half of heated milk mixture and mix together.
Add both milk components back to saucepan and bring to boil. Lower heat and cook until it thickens, about 8-15 minutes.
Meanwhile, cook pasta for five minutes. Drain and set aside.
Once milk mixture has thickened, take saucepan off heat and add cheese.
In large heat-proof bowl, combine cooked pasta, chorizo, diced green chiles and cheese sauce. Pour mixture into 2-quart oval baking dish and top with tortilla chips.
Bake for 20 minutes. Serve immediately.
This dish packs a lot of flavor from the Mexican chorizo and two types of chiles. You can serve it with a side of guacamole or salsa