Depending on the day, I use a number of different methods and ingredients.
I make Japanese curry most days with S&B Medium Roux, but I also make it from scratch regularly as well which allows for the use of various curry powders.
We prefer either shrimp or chicken curry and the additions from what could be the standard Carrots, Potato and Onion include at times:
- Shiitake mushrooms dehydrated and sauteed
- Frozen peas
- Yukon vs russet potatoes
- Honey, Worchestershire sauce and soy sauce on occasion.
- Dark chocolate sometimes
- Grated apple (frequently)
- Canned tomatoes
I have spent a total of 15 years of my life back and forth in Japan from the time I was a small child. We regularly had a variety of Japanese Curry, either in franchise restaurants, or made at home. It can be extremely versatile and all up to your taste. The best way to decide what to put in YOUR curry is to experiment.
Finally, it is obviously best served with JAPANESE type rice. Short or medium grain, but short grain, while expensive, is really the best.
Best presentation is formed rice on one side of a large, shallow soup/salad bowl and the curry then spooned into the other side to ring the edges of the rice. A good pinch of fukujinzuke along the edge or topping the rice makes the perfect dish!
Bon Appetit...and itadakimasu!
Added: This question started me thinking about dinner and it gave me an itch, so I made exactly what we're talking about! Included onions, Yukon Potatoes, carrots, celery, Shiitake mushrooms, frozen peas, grated apple, Worcestershire sauce, honey, and used S&B Medium Curry roux.