Clarified butter is butter with the protein foam and the milk solids removed. When they're gone, what's left (a) doesn't go rancid without refrigeration and (b) doesn't burn when you use it to fry things.
The easiest way to clarify butter is in your microwave, but be sure to work slowly and gradually because the easiest way to make a big mess of your microwave is to get distracted when clarifying butter.
Put the butter straight from the refrigerator into a */deep/* microwave-proof bowl or pitcher. To clarify one stick ( ¼ pound = ½ cup) of butter you should use a deep container that holds at least two cups, and you need to work slowly.
Nuke the butter on the setting one notch above "defrost" until it separates into three layers:
The foam and the milk solids are yellowish-white, the clarified butter is golden.
Let the container stand till it's no longer at all warm to the touch.
Put it in the refrigerator.
After the container in which you microwaved the butter is completely cold, use a spatula to scrape off the top foamy layer and put it in a different container, which we'll call Container B.
Scrape off the clarified layer and put it into a container with a cover. If you have done a perfect job, this clarified butter does not need to be refrigerated. Myself, I'm not a perfect-job person, so I store mine in the refrigerator.
Put the congealed foam from Container B back into Container A, with the milk solids at the bottom. Return Container A to the microwave and nuke it at the same low temperature till the foam and milk solids have caramelized and smell like the butterscotch of the gods, usually 2-3 minutes.
Use the caramelized leavings to spread on bread or crumble over cottage cheese. Sugar or salt it, up to you. There's not enough to share. Keep it your own little secret.
If you'd rather not make it yourself, you can buy high‑quality clarified butter as "ghee," which is its name in one of the 600 languages spoken in India. King Arthur Flour's website carries Purity Farms, the brand I use when I don't have my own on hand. But the boughten version doesn't come with the caramelized treat.