Not really a recipe. I cook like my Mama. Start with frozen shredded hash browns and white gravy mix.
Pour a scant cup of water and a couple cups of milk in a pan. Heat till warm and add a quarter cup, more or less, of your favorite white gravy mix. Brown a half chopped onion in some bacon grease, or maybe butter. Add about a fourth cup water and heat a couple minutes. Add this to your soup base. Add hands full of hash brown potatoes till it looks like potato soup. Heat till it bubbles. Cook about 5 minutes or so. If it is too thick, add more milk. If it is not thick enough, add more gravy mix. If it doesn't look like enough potatoes add more, and cook it longer. If you want more flavor, use the whole onion. I sometimes add some chopped cooked bacon or chopped ham. Some add cheese, but I do not want cheese in my potato soup. Salt and pepper to taste.
About 15 to 20 minutes, start to finish. Enjoy.