Ochazuke, a Japanese soup in which rice and other ingredients are served in a bowl of green tea, has been made since the Heian period to repurpose leftovers into a soothing meal. The main appeal of this dish is the lightly roasted aroma of the tea that's nice and warming on a cold day, and it's a great vehicle for leftover protein like tuna.

If you have some leftover rice and some green tea, you're pretty much set to make ochazuke. The rice is steeped in the tea so that it can take on the toasty, herbal flavor of the liquid, and while the most popular fish to add to ochazuke is salmon, which makes it "sake chazuke," leftover tuna steak or canned tuna also works well.

You can even cook a whole filet of tuna by steeping it in the hot tea, and other popular ochazuke ingredients and seasonings include crispy rice balls, nori (seaweed), fish roe, ume (dried pickled plum), sesame seeds, and more. You can also make ochazuke with dashi stock instead of tea, pouring it over the rice and ingredients in the same way.