I stopped at United Noodles tonight to stock up on some Japanese food staples. They had Golden Curry roux on sale so I grabbed a box. Even though Japanese curry is usually made on the stove in a pot, it works pretty well in the slow cooker.
Throw the whole box in the slow cooker with 6 cups of water. Set it to high if you are in a hurry. Otherwise, set it to low and let it simmer until it gets to the thickness you want.
Japanese curry is similar to chili in the USA. People work long and hard on honing their own personal recipes. They add things like grated apple to sweeten the roux. Some add coffee or chocolate to give the roux some low end.
Check out CoCoIchiban’s menu. Anything you like can go on top of your curry. That’s why curry rules.