In a medium saucepan begin melting the butter over low heat.
Once butter is just melted, add garlic, onions, korerima, koseret, besobela, and turmeric.
Increase to medium heat and bring mixture to a boil, then reduce to low or medium-low and simmer for about 20 minutes, stirring often.
Once mixture is completely cooked, turn off heat and allow to rest for a minute.
Line a fine-mesh strainer with a folded piece of cheesecloth (the cheesecloth helps to catch any milk solids). Set the strainer on top of storage container of your choice.
Carefully pour hot niter kibbeh through the strainer to remove all the solids.
Using the back of your spoon, mash the solids to strain as much oil out as possible.
Cover and store in the refrigerator and use in your favorite Ethiopian dishes.
Keeps for about 1 month.