Squeeze the chorizos out of their casings and break into bite-size pieces. Place the olive oil in a non-stick skillet over medium heat and cook the chorizo until well browned about 10 minutes. Transfer to a plate lined with paper towels to drain the excess grease.

Cook the pasta in salted boiling water until al dente. Drain through a colander and set aside (do not rinse!).

Preheat the oven to 350. Lightly butter a 9 X 13 pan. Toss together the pasta, chorizo, and Cotija in the baking dish.

To prepare the mornay sauce, heat the milk in a small saucepan over medium heat. As soon as the milk starts to steam and tiny bubbles form around the edges of the pan, turn off the heat. Place the butter in a medium saucepan and melt over medium flame. Add the flour and stir with a flat-edge wooden paddle just until the roux begins to take on a light brown color, scraping the bottom to prevent burning, about 3 minutes. Slowly add the milk, chipotle peppers, and cumin, stirring (or whisking) constantly until the sauce thickens enough to evenly coat the back of a spoon–a finger drawn along the back of the spoon should leave a clear swath. Remove from heat and add most of the Lincolnshire Poacher to the sauce–reserve a handful or so for topping–and stir until completely melted. Season with salt and pepper to taste. Be careful with the salt, as the cheese is already salty.

Pour sauce over pasta and stir all around to coat. Top with the reserved Cheddar and green scallions. Bake for 25 minutes or until crispy brown on top. Allow the dish to cool for 5 minutes before serving, then garnish with a bit more freshly chopped scallion if desired.