Toasted sesame and ground perilla are the quiet finishers behind so many Korean dishes. Both are far better done fresh than bought pre-ground.
Toast low and slow
Dry pan, medium-low heat, and keep them moving. Sesame is ready when it is golden and starting to pop; perilla when it smells nutty. They go from toasted to burnt in seconds.
Grind, do not pulverise
A few turns in a mortar cracks the seeds and releases the oils. Leave some texture; a coarse grind has more to give than a fine powder.
Use and store
Crushed sesame over namul and rice; perilla powder stirred into soups like deulkkae-tang for body and nuttiness. Keep both in the freezer.
Eric’s tip
Pre-ground seeds go stale and flat fast. Toast and grind small batches, and only when you are about to use them.