For the pasta and sauce: Bring a pot of water to a boil. Add the pasta and cook according to the instructions on the package. Drain and set aside.
Set a medium saucepan over low heat. Add the evaporated milk, Buffalo sauce and mustard and whisk until uniform and smooth. Toss the Cheddar and pepper jack with the cornstarch in a bowl until the cheese is totally coated, then add to the saucepan. Whisk in the blue cheese and heat, stirring constantly, until all the cheese is melted and the sauce is silky and smooth, about 5 minutes.
For the mix-ins: Meanwhile, lay out the chicken skin flat in a pan without overlapping the pieces. Cook on high heat until crisped, 5 to 8 minutes. Chop into pieces.
Add the pasta to the sauce and stir until completely coated. Add the crisped chicken skin and shredded chicken and stir. Mix in the blue cheese.
Transfer to a serving bowl and garnish with the celery leaves. Serve with celery stalks as "spoons."