Japanese are quite fond of curry. It was said the original Japanese curry was first served on Japanese Navy ships and is based on English modifications to Indian curry. Now, in Japan, many curry restaurants have proliferated including ones serving very authentic regional curries such as those in India, Thailand, and Nepal in addition to Japanese style curry. Japanese have three choices if they want to eat curry at home; 1. make it from scratch using authentic methods and spices, 2. Use commercial "curry roux" which is readly available and 3. or heat up Curry-in-a-pouch which is called "retoruto-kare" レトルトカレー. Food-in-a-pouch or "retort pouch" / "retortable pouch" was initially developed by the US military to replace canned or bottled food, reduce the weight and waste and also to make a meal-ready-to-eat (MRE) that could be heated quickly. It was also used during space travel. In the US, food-in-a-retort pouch did not become very popular among the general populace, perhaps, because of the widespread use of frozen food. But, in Japan, curry-in-a-pouch has been extremely popular. One servings of curry comes in a pouch and the price ranges for $1 to $10 encompassing mass-produced cheap varieties to high-end varieties with a restaurant's or hotel's name attached to it. In recent years, another category of curry-in-pouch called "gotouchi kare" ご当地カレー is getting popular. There are even specialized websites from which you can buy quite interesting varieties of "locale-specific" or "Gotouchi" curry. We recently ate one such example which was sent to us as part of my mother's New Year "care" package. This one was scallop curry from Hokkaido. I added shrimp, blanched green beans and broccoli. Of course, I also served Japanese curry condiments "rakyo" ラッキョウ and "fukishin-zuke" 福神漬け.
The curry contained a goodly number of scallops which were nice and tender but I am not sure it added anything substantial to the curry. The curry roux was moderately hot and had nice flavors and texture. My wife added yogurt to dampen the heat (and also because she just likes yogurt in her curry.)
This seafood curry in a pouch came from "Sato suisan" 佐藤水産 or Sato seafood in Sapporo. I found out that, beside selling Hokkaido seafood products, this company also runs seafood restaurants with one located near the opening of Ishikari river 石狩川 called "Old River" restaurant. This curry is supposedly from this restaurant using fresh Hokkaido vegetables and seafood (two varieties of seafood curry are available; scallop 帆立 or sea whelk ツブ) without animal fat or meat.
As per the directions on the back of he package, I boiled the pouch in water for 5 minutes. They also recommend adding cooked (sautéed in butter) vegetables.
I thawed uncooked shell-on shrimp, cleaned and sautéed them in butter with blanched green beans and broccoli seasoned with salt and pepper.
We shared one pouch between the two of us and put it over rice (pre-cooked frozen rice microwaved to thaw). The scallop was tender and the roux had nice heat, texture, and flavors albeit not particularly special. (My wife thought it tasted very similar to the curry I make with Japanese curry roux, although this curry doesn't include any animal products but the roux does). Certainly this is a very convenient way to enjoy curry at home.
My mothers package also included the "whelk" curry in-a-pouch which tasted very similar to the scallop curry but with the inclusion of "rubber tire" chewy whelk. My wife "graciously" passed all the welk she could find in her dish to me--even the one she had been unsuccessfully chewing on for awhile.