01 -
Heat the oven to 375°F (190°C). Grease a 9x13 inch baking dish with butter or cooking spray and set aside.
02 -
Bring a large pot of well-salted water to a boil. Cook the penne for 2 minutes less than the package directions. Drain and set aside. It will finish cooking in the oven.
03 -
Melt the butter in a medium saucepan over medium heat. Whisk in the flour and cook, stirring constantly, for about 1 minute until the mixture smells slightly nutty and the raw flour taste is gone.
04 -
Pour in the milk in a slow, steady stream while whisking constantly. Cook for 4 to 5 minutes until the sauce thickens enough to coat the back of a spoon. Stir in the garlic powder, cumin, salt, and pepper.
05 -
Remove the saucepan from the heat. Add 1 cup of the cheddar and 3/4 cup of the Monterey Jack in two or three handfuls, stirring after each addition until fully melted and smooth.
06 -
In a large bowl, stir together the drained pasta, the cheese sauce, and the chopped green chiles until everything is evenly coated.
07 -
Pour the mixture into the prepared baking dish. Scatter the remaining 1/2 cup cheddar and 1/4 cup Monterey Jack over the top. Bake for 20 to 25 minutes until the top is golden and the edges are bubbling.
08 -
Let the dish sit for 5 minutes before scooping. This gives the sauce time to firm up slightly so it holds on the plate.