The best replacement for sesame seeds is flax seeds.

The best alternatives to sesame seeds are rated as following:
★★★★★  flax seeds
★★  poppy seeds
★★  sesame oil
★★  sunflower seeds
★★  white sesame seeds
★  pumpkin seeds
★  toasted sesame seeds
★  unhulled
★  hulled
  hemp seeds
  tahini
  til
  sesame seeds
  black sesame seeds

Your alternative for sesame seeds is not listed? Suggest!
Speaking about sesame seeds, one probably shouldn't forget about tuna.

Other search terms related to sesame seeds and their ratings are:
★★★★★ tuna
You have in mind a companion for sesame seeds and it is not yet here? Propose!



Google Trends

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sesame seeds
flax seeds
poppy seeds