Dry curry is a uniquely Japanese dish, much like the stew-type of Japanese curry. Dry curry is really well suited to bentos. The spicy curry aroma is appetising yet not overwhelming, and the combination of salty, spicy and sweet flavors really gets me going.
The recipe for a more traditional ground meat based dry curry has already been posted on Just Hungry. This is a vegan version that uses cooked soybeans or crumbled tempeh. It's so rich in flavor that even non-vegetarians won't miss the meat. It's also very easy to make, though a food processor helps for chopping up all the vegetables.
Both the meat based and this soybean based dry curry mixes freeze very well, making them perfect freezer staples.