Wash potatoes thoroughly. Leaving skins on, quarter each potato. Boil potatoes until fork-tender. Do not overcook. Drain.
Use a potato masher to coarsely mash the potatoes. Stir in cheeses, onions, garlic, salt and pepper.
If using leftover mashed potatoes, stir cheeses, onions, garlic, salt and pepper into mashed potatoes for the potato cake filling.
Combine breadcrumbs and flour in a pie tin or round cake pan. In a separate bowl, combine eggs and milk.
Divide the potato mixture into 12 equal portions. Start by evenly dividing it in half, then half again, etc until you have 12 portions. Shape each portion into a patty (like a hamburger patty).
Dredge each patty into the breadcrumb mixture, then dip into the milk and egg, then coat again with breadcrumbs.
Place the breaded patties on a cookie sheet. Cover and chill for one hour.
Heat 1 cup of vegetable oil in a large skillet. Pan fry the cakes on medium heat for 2 to 3 minutes on each side or until browned. Drain on paper towels.
Serve with Creamy Dipping Sauce, ranch dressing, sour cream, or 1 cup sour cream mixed with 1/2 cup salsa. Garnish with chopped green onion or chives.