This was inspired by the vegan cooking by a Buddhist monk in Kyoto. He briefly cooked the nagaimo 長芋 rounds in broth, soy sauce and mirin to season it before making a type of tempura called "Isobe-age" 磯辺揚げ with the batter containing dried "aonori" 青海苔. I also made salmon sausages we got from my mother for new year into a similar tempura. I served it as a drinking snack with green tea salt, wedges of lemon and skinned Campari tomato.
I cooked the nagaimo a bit too much but I just used the leftover nagaimo dish and converted to the current dish.
Ingredients (for two small servings):
Nagaimo, peeled and cut into half inch thick rounds (four)
Dashi broth, soy sauce, mirin and sake
Salmon sausages, sliced diagonally in half inch thick (four)
For the tempura batter
Cake flour and potato starch
1. Cook the nagaimo in seasoned broth (Japanese broth seasoned with soy sauce, mirin and sake) for few minutes and let it cool in the broth (see below, this one is cooked longer than called for in this dish).
2. Make the tempura batter by mixing the flours and "aonori" with cold water until desired consistency (I made this rather runny). Coat the nagaimo and sausages.
3. Heat vegetable oil (I used peanut oil) to 350F and deep fry for few minutes.
4. Drain and serve immediately.
Since this was converted from "simmered Nagaimo" dish, the nagaimo was cooked more than needed before it was deep fried. Still, it had nice crunchy texture. It has nice crust with aonori flavor. The salmon sausages also tasted much better than when we tasted as is. This was unusual but quite good tempura items.