Grate the zucchini, and drain the excess liquid and absorb with a paper towel.
Add the ground turkey to a large mixing bowl, then add the shredded zucchini, garlic salt, pepper, bread crumbs, parsley, mayonnaise, and shredded cheddar cheese.
Mix with a spatula until well combined.
Start heating a large pan with medium heat while forming the patties. If you have two pans, start heating the other for the buns.
Wet your hands with a little water, take about 3 tablespoons of the ground turkey mix and roll in a ball. Then press it and shape it into a patty with your hands. Place the patties onto a large plate, and repeat with the rest of the turkey mixture.
Add 1 teaspoon oil to the pan, and when the oil is hot add around half the turkey patties to the pan. Don’t overcrowd the pan. Wait 3-4 minutes, and flip them, add a slice of cheese to each and cook for an additional 3 minutes.
Remove from the pan, and place on a large clean plate to rest. Repeat this step to finish cooking the turkey patties.
Add the butter to the other large pan or to the turkey burger pan once done. Once the butter has melted, add the slider buns with the inside of the bun facing down. Repeat until the slider buns are all browned.
Fill your browned slider buns with Thousand Island dressing or ketchup, a turkey patty, lettuce, tomato, red onion and any other toppings you fancy.