Basil seed — sold as sabja, tukmaria or falooda seed — is the tiny black seed of sweet basil (Ocimum basilicum), the same garden herb grown for its leaves. The dry seeds are nearly flavourless, but soaked in water each one swells in minutes inside a translucent grey jelly coat, turning into a cluster of soft, frogspawn-like gel beads that are stirred into sweet drinks, falooda, sherbets and Asian desserts for their cool, slippery crunch.