Heat the oil in a 12-inch nonstick skillet over medium-high heat. Add the potatoes and press into the bottom of the skillet, forming a solid "pancake". Cook for 10 minutes or until the potato pancake is well browned on both sides, carefully turning the potato pancake over halfway through the cook time. Do not stir. Remove the potato pancake from the skillet and keep warm.
Add the chicken to the skillet and cook until well browned, stirring occasionally. Stir in the zucchini and picante sauce and cook until the zucchini is tender and the chicken is cooked through, stirring occasionally. Spoon the chicken mixture over the potato pancake. Sprinkle with the cheese.
Cooking Basics: You can flip the potato pancake with a large spatula to brown both sides, or you can brown the bottom and slide the pancake out of the skillet onto a large plate. Place the skillet upside-down over the pancake and invert so that the pancake lands in the skillet, uncooked-side down. Cook until the bottom is well browned.