Add mayonnaise, milk, and cheese to a small mixing bowl. Blend well and set aside.
Shred 1 carrot and 1 stalk of celery. Slice remaining veggies into sticks.
Toss shredded veggies into a large mixing bowl, along with the ground chicken, panko, paprika, egg, and garlic powder. Mix until combined, then split into 8 equal portions and shape into patties.
Spray a large skillet with cooking spray and heat over medium.
Add patties to the hot skillet and cook 3-4 minutes per side until no longer pink in the center. Set aside and continue with remaining patties until all have been fully cooked.
Divide rolls in half, spreading a small amount of the mayo mixture onto each one; add some spinach and a chicken patty to each.
Serve sliders with apple slices and veggie sticks on the side. (Serving size: 2 sliders, 2 rolls, 1/2 apple, 1/2 cup spinach).