*Karashi* is spicy Japanese-style mustard made from crushed mustard seeds—*Brassica juncea*, a species of mustard also known as brown mustard or Chinese mustard—and horseradish. You can use *karashi* in many applications, including as a condiment, pickling agent, or filling. The hot mustard can add a punch to dishes like [*gyoza* dumplings](https://www.masterclass.com/articles/gyoza-recipe), *tonkatsu*, and chicken *katsu* and impart notes of peppery heat into salad dressings and soups. *Karashi* is a potent vehicle of mustard’s signature heat, thanks to the addition of peppery, bitter horseradish. Unlike the vinegar-driven heat of Western mustard, *karashi* mustard evokes the same tingly feeling as freshly grated [wasabi](https://www.masterclass.com/articles/what-is-wasabi). *Karashi* is used to bring heat and dimension to dishes across Japanese cuisine. 1. __As a condiment__. A traditional plate of [tonkatsu](https://www.masterclass.com/articles/how-to-make-tonkatsu) (fried pork cutlet) wouldn’t be complete without a swipe of *karashi*. The hot mustard is a traditional condiment for snacks like *shumai* dumplings (traditional Chinese dumplings), and *karashi* packets are included with packages of *nattō*, sticky fermented soybeans. 2. __As a filling__. *Karashi renkon*—lotus roots stuffed with a mix of [miso](https://www.masterclass.com/articles/what-is-miso-easy-miso-broth-recipe-with-chef-gordon-ramsay) and *karashi*, then sliced, battered, and fried until crispy—is a regional specialty of Kumamoto, a city in Kyushu. 3. __As a pickling agent__. *Karashi* is a key ingredient in *karashizuke*, a kicky realm of *[tsukemono](https://www.masterclass.com/articles/tsukemono-guide)* pickles in which a bit of *karashi* is added to the base of [sake](https://www.masterclass.com/articles/sake-guide) lees before pickling. *Karashi-nasu*, pickled [Japanese eggplant](https://www.masterclass.com/articles/roasted-japanese-eggplant-recipe), is one of the more popular kinds of *karashizuke*. 4. __As a seasoning__. *Karashi* is used to season dishes like *oden*, a one-pot stew made with a [dashi](https://www.masterclass.com/articles/dashi-explained) broth. You can also mix it into spreads and dipping sauces for sandwiches and salads, like *karashi* butter, *karashi* mayonnaise, and *karashi-su*-miso, a mustard-miso dressing. *Karashi* is sold in pre-made paste or powder form, which allows for a personalized level of spiciness. Simply combine a few teaspoons of *karashi* powder with warm water to preference, and mix until paste forms. Cover the mixture with plastic wrap and allow it to steam for five minutes for best results. Become a better chef with the [MasterClass Annual Membership](https://www.masterclass.com). Gain access to exclusive video lessons taught by the world’s best, including Niki Nakayama, Gabriela Cámara, Chef Thomas Keller, Yotam Ottolenghi, Dominique Ansel, Gordon Ramsay, Alice Waters, and more. *Karashi* goes way beyond your average yellow mustard: It’s a devilish, sunny, make-your-nose-run kind of mustard.