Glossary - Ingredients

Komatsuna/Japanese mustard spinach


In season from December to March, the Japanese mustard spinach (komatsuna) is of the Brassica rapa plant species and is said to be most delicious during the snowy season.



This leafy vegetable is abundant in beta carotene, vitamin C, calcium and iron. In fact, Japanese mustard spinach is said to contain 5 more times calcium than spinach.


Select Japanese mustard spinach that is bright green in color, with leaves that are not drooping or torn or changing color. Wrap in paper towel or newspaper and store in a refrigerator.

Cooking tips

Japanese mustard spinach is not very astringent (bitter), and as such can be used without parboiling in boiled and simmered dishes. Also enjoyable in sautéed dishes, as a garnish for simmered fish and in the traditional Japanese New Year’s dish of “zoni” (soup containing mochi (rice cakes)).

Cooking Basics

Greens - making a cross cut into the root

As the thick root takes longer to cook through, make a cross cut into the root to allow for faster cooking. This will also allow water to be absorbed more easily to increase crispiness.

Greens - soaking in water to revive

If the greens themselves are in good condition, they will have good texture when used in stir-fried and simmered dishes. Also, this step allows dirt trapped in the roots to be removed naturally.

Greens - separating leaves and stems

The cooking time required for stems and leaves differs. When you want to quickly saute or boil, stems and leaves need to be cut apart and added in at different times. First add in the stems, and once softened, add in the leaves to allow for even cooking.

Greens - boiling in salt

Add salt to plenty of boiling water to achieve salt concentration of about 1 - 2%, then add in the greens from the roots. After boiling for about 20 seconds, remove into cold water.

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