Cha-zuke or ocha-zuke (from o + cha tea + tsuke submerge) is a simple Japanese dish made by pouring green tea, dashi, or hot water over cooked rice roughly in the same proportion as milk over cereal, usually with savoury toppings.
Common toppings include tsukemono, umeboshi (both types of pickles), nori (seaweed), furikake, sesame seeds, tarako and mentaiko (salted and marinated Alaska pollock roe), salted salmon, shiokara (pickled seafood) and wasabi.
The dish is easy to make and provides a way to use leftover rice as a quick snack. It is also known as cha-cha gohan.
This dish first became popular in the Heian-era, when water was most commonly poured over rice, but beginning in the Edo-era, tea was often used instead.
In Kyoto, ocha-zuke is known as bubu-zuke. When a Kyoto native asks if a guest wants to eat bubu-zuke, it really means that the person has overstayed and is being politely asked to leave.
Since the 1970s packaged "instant ocha-zuke", consisting of freeze-dried toppings and seasonings, have become popular.