Preheat oven to 400 degrees and line large baking sheet with parchment paper.
Meanwhile add gluten free crackers of choice to food processor and pulse till crumbs.
Place enough crumbs on a plate to do one patty and set aside.
Add cold mashed potatoes to mixing bowl.
Stir in green onions, and cheddar cheese.
If needed you can add a little bit of milk to loosen up the potatoes.
Using an ice cream scoop spoon out enough for one patty and shape with hand and pat together.
Place formed patty on plate with cracker crumbs and coat both sides well. Then place on baking sheet.
Repeat process adding more crumbs to the plate till you've done all patties.
Bake in preheated oven 20 minutes and then carefully flip and bake another 10-12 minutes.
Remove from oven and allow to cool at least 10 minutes before serving.