Tonkotsu broth, which is commonly used in Japanese cuisine, is made from simmering and boiling pork bones over an extended period. This process extracts the flavors and nutrients from the bones and results in a creamy, white, and opaque soup stock. Tonkotsu broth serves as the base for dishes like Tonkatsu or other soup-based dishes. It is known for its rich, savory, and umami flavor profile.