Japanese
Cut the onions into thin wedges and the carrot and potatoes into bite-size chunks.
Heat the oil in a large pot over medium heat and brown the pork for 4 minutes.
Add the onions and cook for 5 minutes until soft, then add the carrot and potatoes and stir for 1 minute.
Pour in the water, bring to a boil and skim off the foam, then cover and simmer for 20 minutes, until the vegetables are tender.
Turn off the heat, break the roux into pieces and stir until it has fully dissolved.
Simmer over low heat for 10 minutes, stirring often, until the sauce is thick.
Spoon the curry next to the rice on each plate and serve.