Add chicken tenderloins to a bake sheet. Drizzle olive oil on both sides of the chicken tenders. Season with salt and pepper. Bake chicken for 5 minutes on each side or until no longer pink on the outside. Allow the chicken to rest. Reduce oven to 350 degrees F.
Make the buffalo sauce while the chicken is in the oven: melt 2 tablespoons Land O Lakes butter in a sauce pan on medium. Add celery salt, salt, cayenne pepper and chili powder and stir. Add hot sauce and cook for 4 to 5 minutes. Remove from heat.
After the chicken has cooled, slice the chicken against the grain and then dice into pieces. Put chicken into a bowl and pour the buffalo sauce into the bowl and mix until chicken is coated in buffalo sauce.
Make sure oven is set to 350 degrees F. Arrange the Athens Foods mini fillo shells on a baking sheet. Add buffalo chicken to fillo shells evenly. Bake for 8 to 9 minutes.
Remove from oven and drizzle blue cheese or ranch dressing on top and serve immediately. (Optionally: serve with celery sticks.)