120+ min (2+ hrs) 2 easy 30 min boil deep-fry karashi make ahead Recipes - Japanese reduced sodium renkon

Karashi renkon / deep-fried lotus root with mustard-flavored miso

A regional specialty with 400 years of history from Kumamoto in southern Japan. It makes a great appetizer, as the dish was originally designed to stimulate the appetite and improve the health of a great lord. Sweet miso blended with spicy karashi mustard releases a soft yet pungent aroma as you bite into the crunchy lotus root, making you want to take another sip of sake or bite of plain rice …
Actual cooking time is not particularly long, but preparation does take some time to let the lotus root and filling work on their own to stabilize the karashi-miso mixture, so plan ahead.

Whole recipe:
419 calories; 7.1 g protein; 26.3 g fat; 38.3 g carbohydrate; 32.0 g net carbs; 444 mg sodium; 14 mg cholesterol; 6.3 g fiber

1/2 of recipe:
210 calories; 3.6 g protein; 13.2 g fat; 19.2 g carbohydrate; 16.0 g net carbs; 222 mg sodium; 7 mg cholesterol; 3.2 g fiber

1/3 of recipe:
140 calories; 2.4 g protein; 8.8 g fat; 12.8 g carbohydrate; 10.7 g net carbs; 148 mg sodium; 5 mg cholesterol; 2.1 g fiber


(Serves 2-3)

1/2-1/3 section (approx. 150 g) renkon lotus root (135 g with skin, 121 g skinned in photo)
1-2 tsp rice vinegar (to boil renkon; not in photo)

For filling
40 g (slightly more than 2 tbsp) Saikyo miso
20 g fresh (or 8-10 g dry) okara soybean pulp (10 g dry okara soybean pulp in photo)
1 tsp karashi powder
1 tsp warm water (to mix with karashi; not in photo)

For tempura batter
30 g flour
30 cc water
1/4 egg yolk (not in photo)
1/4 tsp ukon turmeric powder

Flour (to dust renkon lotus root before applying batter; not in photo)
Oil for deep-frying (not in photo)


Skin or scrub renkon lotus root skin, place in pot with water and rice vinegar, and cook for 5-6 minutes once boiling.

Drain, and dry in cool place (or fridge) for several hours to overnight.


Mix karashi powder and warm water well.

Mix Saikyo miso, karashi paste and okara soybean pulp well. 

Form mound.


Press renkon lotus root onto miso mixture mound.

Repeat until miso mixture comes out from top. 

Scrape off miso mixture
that comes out, and let sit for a few hours to overnight. 

(After 1 hour
at left; okara swells as it absorbs moisture, pushing up excess miso

Heat oil for deep-frying.


Mix all ingredients for batter.


Remove any excess miso mixture from renkon, and put 1-2 skewers into its side (to hold in oil while deep-frying).
Dust with flour, and remove excess.

Dip in or spoon over batter.


When oil is hot enough (150-160C/300-320F), put renkon in oil. Hold in oil without letting renkon touch bottom of pot.

Spoon hot oil over renkon to cook all surfaces.
(Once all surfaces are
cooked, renkon can be released from skewers into oil.)

Raise oil
temperature somewhat, and continue cooking renkon until slightly golden
while flipping or rolling several times.

Hold renkon with chopsticks or
tongs, with one end still immersed in oil to draw back all excess,
remove from oil while gently shaking, and transfer to paper-lined plate
to further eliminate excess oil.  


Slice as desired, and serve.


  • If okara is not at hand, bread crumbs or crumbled fu wheat gluten cakes can substitute.
  • The above proportion of karashi makes the dish relatively spicy and not suitable for kids. Try less karashi if unsure. (Not especially spicy for those accustomed to spicy food or who order dishes with 4- or 5-star spiciness at Thai or Korean restaurants in the US.)
  • Saikyo miso above is originally sweet and requires minimal additional sweetener. If using other shiro white miso, you might want to add more mirin/sugar.
  • Nutrition figures are based on an oil absorption rate of 15% (24 g canola oil absorbed by ingredients).
  • This dish is said to have been created at the suggestion of a Buddhist monk for a nutritious diet for a feudal lord of the time (Hosokawa Tadatoshi [1586-1641]), who was in poor health and had little appetite. Despite the excellent nutrition of lotus root, the lord originally refused to eat it, as he did not like the idea of eating something that grows in mud. But the lord did not mind eating deep-fried lotus root, especially when it was filled with spicy and sweet miso, and his health was eventually restored. It is also said that due to the resemblance of karashi renkon‘s cut surface with the Hosokawa family crest, the recipe for karashi renkon was kept secret until the 19th century.

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