Heat oil in pan on medium and fry mortadella till it starts to crisp. Remove and set aside
Add shallots, garlic and pistachios and cook 1-2 minutes.
Add some pasta water to prevent burning and continue to simmer
Add the mortadella back
Add 1/2 cup or more pasta water and the almost done pasta (maybe a minute or 2 before done). Cook and stir till pasta is done and a sauce is created, tossing all the while
Turn off heat. Add the cheese and toss till incorporated. Add more pasta water if needed.