Grate some cheese and spread it on a thin, even layer on a microwave-safe plate covered in parchment paper. Microwave the cheese in 30-second bursts for a total of 2 minutes, which will cause the fat to separate out and leave you with a hardened disc of cheese. Once the hardened cheese has cooled, you can break it up into pieces and grind them into powder in a food processor. Add a pinch of cornstarch to improve the texture.