Toast the sesame seeds in a dry frying pan on a high heat until golden.
Crush in a pestle and mortar until they’re broken down into a dry paste.
Add all the ingredients to a bowl.
Mix until fully combined.
Notes
Play with the ratio: Equal parts mayo and tonkatsu sauce is the sweet spot, but make it yours — more mayo for something creamier and milder, more tonkatsu for tang and sweetness.Toast those seeds: Don't skip this step. A dry pan on high heat, 1-2 minutes, and the flavour completely transforms. Keep your eyes on them though — they go from golden to burnt in seconds.Grind them properly: Crush the seeds into a dry paste rather than leaving them whole — it blends into the sauce beautifully and gets the flavour into every bite.Chill before mixing: If you're making the mayo and sauce from scratch, let them cool in the fridge first. You'll get a much thicker, more satisfying result.No sesame? Leave them out entirely and the sauce still sings. Ground toasted peanuts or other roasted nuts work brilliantly as a swap.Storage: Into a sterilised airtight jar, fridge, up to 3 weeks. Clean spoon every time and give it a stir before serving.