Peel the large potato and microwave it on high for approximately 5 minutes or until tender. Let it cool, then shred using a box grater.

In a mixing bowl, combine the shredded potato, cream cheese, shredded cheese, minced garlic, finely chopped green chile, garlic salt, and black pepper. Optionally, add finely diced onion. Mix until well integrated.

Heat a thin layer of vegetable oil in a skillet over medium heat. Form the potato mixture into small cakes and fry on each side for about 3-4 minutes until golden brown and crisp.

For larger batches, preheat your oven to 175°C (350°F). Coat a baking dish with oil, spread the potato mixture evenly, and bake for 30 minutes until crisp.

While the cakes are cooking, blend sour cream with finely chopped green chile and black pepper to taste for dipping.

Serve the hot potato cakes with the green chile sour cream for dipping.