Add water, dry pinto beans, 1 onion (cut in half) and 2 teas salt to an Instant Pot or slow cooker
If using an instant pot, set it manually to 25 minutes with it sealed. If using a slow cooker set it to high for 8 hours
Heat the oil in a non-stick pan and sauté the diced onion and minced garlic for 4-5 minutes until soft
Add cooked beans with liquid, 1 ladle full at a time, to the pan with the onions and garlic.
Mash with a potato masher as if fries in the pan. Add the remaining salt
Continue to add 1 ladle of beans with liquid at a time, mashing it and letting it thicken up until all of the beans are transferred and mashed
Discard remaining liquid
Top with melty white cheese, onions, cilantro or avocado
Serve and enjoy!