Preheat your oven to 375 F.
Dice the garlic and shallot and set aside.
Grate the Gruyere, Pecorino, and Cheddar is a food processor.
Add the pancetta and oil to the pan.
Cook pancetta and oil on medium heat for 10 minutes until the fat starts to render and starts to turn golden.
Add the diced shallot, garlic, and chili powder and cook for an additional 2 minutes then remove from the heat and set aside.
Add the butter to the hot pan and melt, 1 1/2 minutes.
Add the flour and mix, cook 4 minutes until golden brown to form a roux.
Cook cornetti in a large pot filled with salted water for 3 minutes then drain, it will be very al dente.
Add milk to the empty pasta pot and warm for 4 minutes.
Start to slowly add the milk ladle by ladle to the flour and butter roux in the pan and cook for 2 minutes.
Add the grated cheese and melt, 3 minutes.
Add the pasta and pancetta and mix.
Sprinkle the grated Parmesan over the dish.
Bake for 20 minutes until golden brown.