Kani to satoimo, horenso no nagaimo soosu guratan / crab, baby taro root and spinach gratin with Chinese yam sauce

A Japanese-style gratin with Chinese yam sauce flavored with white miso and soy sauce. It is much lighter and gentler than a bechamel sauce and cheese gratin. For this gratin, crab is paired with baby taro root -- yet another classic combination in Japanese cuisine -- to make a substantial dish. A bed of sauteed spinach adds additional flavor that also goes well with crab.

<Ingredients>

Handful (140-150 g) crabmeat
2 satoimo baby taro root
Large handful (1/2 bunch) spinach (140 g in photo)
1/2 pack shimeji mushrooms
1 clove garlic
1 tsp olive oil (for spinach saute; not in photo)
Salt & pepper, to taste (for spinach saute; not in photo)
2 tbsp panko bread crumb
1 tsp butter (cut into small pieces)

For broth to cook satoimo
200 cc dashi or water
1 tbsp sake
1/2 tbsp mirin
1 tsp usukuchi soy sauce

For nagaimo sauce
8-10 cm (200 g) nagaimo Chinese yam
1 tsp white miso
1 tsp soy sauce


<Directions>
1.
Preheat oven to 450 F/230 C.

2.

Skin and cut satoimo into 2-3 cm cubes.

In a pot, put all ingredients for satoimo broth and satoimo, bring to boil, reduce heat to medium low and cook until tender (approx. 5 minutes).

3.

Meanwhile, remove root ends of shimeji.
Finely chop garlic.
If necessary, chop spinach.

Grate nagaimo, and mix in miso and soy sauce. 

4.

In a frying pan, heat olive oil, and saute garlic on low heat.

When fragrant, add shimeji, and saute on medium low heat.

When shimeji is almost done (somewhat soft and translucent), add spinach, continue sauteing, salt and pepper, and stir.

5.

Coat gratin dish with olive oil, and put spinach saute.

Put satoimo and crabmeat.

Pour nagaimo sauce, and top with panko.

Top with small pieces of butter.

Bake for 7-10 minutes at 450 F/230 C.
Change oven setting to broil, and cook until top is golden.

<Notes>

• The nagaimo sauce above is at the light end. It can easily be made richer by adding 1/2-1 egg (yolk and egg white or yolk only), milk or mayonnaise.
• White miso is generally mild. However, its saltiness varies by brand: adjust the amount of miso and soy sauce accordingly.
• You can, of course, top this gratin with cheese by itself or in addition to panko. 
• Adding shimeji or other mushrooms to spinach saute is optional.
• Mixing chopped chives in nagaimo sauce is also nice (especially when not using spinach or other greens).