Heat the milk and sour cream together in a saucepan over medium, stirring till it’s smooth and blended.
Stir in lemon juice, salt, sugar, onion powder, and black pepper.
Once it’s all mixed, take the pan off the heat.
Add instant mashed potatoes and cornstarch, then mix until a soft dough forms and pulls away from the sides.
It comes together pretty quickly.
Roll the dough thin between parchment sheets.
Try to keep the thickness even so the chips bake right.
Cut oval shapes and place them on a lightly oiled baking sheet, leaving a bit of space between each.
Bake at 350°F for 12 minutes, flip the chips, then bake another 8 minutes until lightly golden.
Keep an eye on those edges; they can go fast.