Start by rinsing dry beans in a colander.
Pour water into the instant pot. Sprinkle in onions, garlic, oregano, cumin and 1 tsp salt.
Pour rinsed pinto beans into the instant pot and close lid. Make sure you have the pressure valve in the sealed position.
Set the instant pot to the beans function (or manual/high pressure) for 35 minutes. When done, let the instant pot naturally release pressure (this will take about 15 minutes).
When done, allow the beans to cool slightly. Then, transfer beans to a blender with lime juice, remaining salt, and a quarter cup of the remaining bean juice. Reserve leftover liquids from your instant pot to add as you blend if beans are too thick.
When done, beans will be mostly smooth. Serve beans with a sprinkle of crumbled cotija cheese! Enjoy!