Pick out the bad beans and throw them out. Rinse and soak your pinto beans over night for a faster cook (optional).
Drain the beans and put them in a pot deep enough to boil. Add ½ tsp cumin, 1 tsp salt, 1 tsp epazote or Mexican oregano, ½ of an onion, 3 crushed garlic cloves, and enough water to cover the beans by 2-3 inches.
Bring to a gentle boil over medium heat.
Cover and reduce the heat a tiny bit for 1 hour and 30 minutes. You may need a little more time if you did not soak the beans over night. It should be a gentle boil.
Check on the beans about half way through and add HOT water as needed. You want to maintain a water level of about 1 inch above the beans from this point on. Adding too much water will dilute the bean flavor we want.
The beans are ready when you can easily smash them between your fingers (careful! they are hot). Strain the beans, onions, and garlic but don't throw out the bean water. Or you can use a slotted spoon to transfer the beans to the frying pan later and pour the bean water from the pot to save dishes.
Heat some lard (or oil) in a skillet over medium-low heat, then add the finely chopped onions and sauté until fragrant and almost browning. If using neutral oil or lard, season the onions with a pinch of salt. Do not add the salt if you are reusing lard used to make carnitas (this is already seasoned).
Add the chopped jalapenos and sauté for another minute.
Increase the heat to medium high, then add the drained pinto beans.
Begin smashing the beans. I'm use a potato masher, but you can use the back of your spatula or whatever you have that can get the job done.
Reduce the heat to medium after a minute. Keep smashing until you reach your desired consistency, while simultaneously adding the bean water in increments as you smash. I added back all of my bean water in 3-4 batches.
Try the refried beans and add salt, cumin, and/or Mexican oregano to taste. I usually end up adding about ⅛ tsp each to get the perfect flavor. Note: you may not need to add any seasoning if using carnitas lard, since it is already seasoned with these spices.
Once you've reached your desired consistency, remove from heat. I like my refried beans smooth but with little visible little chunks. Some people like it super smooth or chunky- there is no wrong way! Use an immersion hand blender to make it smooth like this one.
Top with your favorite cheese and enjoy :)