Preheat oven to 375 degrees. Spray a 9x12 baking sheet or dish with non-stick cooking spray. Get a cookie cooling rack ready to go. Pop in the oven and bake until slightly toasted, about 4-5 minutes.
If you haven’t already, cut chicken into bite sized pieces, you want two pieces per slider.
Add flour, salt, and garlic powder to a large ziplock bag. Shake to combine.
Add egg and water to another shallow bowl, whisk to combine.
Mix breadcrumbs and ½ cup parmesan cheese to another shallow bowl or plate. Season with a little bit of salt and pepper.
Add chicken to the plastic bag with the flour. Shake to coat chicken. Working in batches, use tongs to transfer the chicken to the egg mixture. Make sure to shake any excess flour off the chicken before adding it to the egg. Coat the chicken in the egg and let any excess drip off. Transfer chicken to the breadcrumbs and coat.
Transfer the coated chicken on to the cookie cooling rack while you bread the remaining chicken.
Once the chicken has been breaded, heat a large skillet to a medium heat. Add 1 ½ tablespoons of the butter and 1 ½ tablespoons of the olive oil to the skillet. Once the butter has melted, add half of the chicken pieces. Cook until golden brown, about 3-4 minutes, flip and repeat on the other side. Transfer chicken to the toasted buns, you want two pieces of chicken per slider. Repeat with remaining chicken.
Top each slider with a tablespoon of marinara. Cover with cheese. Cover with top bun.
Melt remaining tablespoons of butter. Brush tops of buns with butter. Sprinkle with a little bit of Italian seasoning and parmesan cheese. Bake for 10-15 minutes until cheese has melted and buns are toasted.
Use a preheated oven.
Ideally shred your own cheese. Pre shredded cheese contains anti caking agents so it doesn't melt as well.
Spice things up with some pickled jalapeno slices.
You can use chicken tenders or chicken breasts. If using tenders, you want to use two pieces per slider. If using chicken breasts be sure to cut them into similar sizes.