Chop chicken breast into bite-sizes (it's better to remove the chicken skin, but optional). Mince 1 cube of curry roux.
Put chicken breast and minced curry roux (1 cube) into a plastic bag and let the flavor absorb (for about 30 minutes). Then coat with katakuriko.
Slice onion thinly.
Heat frying pan over low heat, then add 1 tablespoon butter. Add onion and sauté generously until brown.
Remove onion from the frying pan, then clean. Heat 1 tablespoon butter over medium heat, and stir-fry the marinated chicken breast until both sides are brown.
Add the cooked onions, coconut milk, and canned tomato.
Simmer for a few minutes over low heat.
Mix everything together and turn the heat off when everything is well-flavored.
Add rest of the curry roux (3 cubes), mix over low heat and simmer.
Add sake and soy sauce to give it a subtle taste, and mix lightly.
Pour over freshly cooked rice or naan. Top with parsley and enjoy.
Story Behind this Recipe
I wanted to eat butter chicken curry like I had at an Indian restaurant, so I made it at home. I dunked some bread into it the next morning - the flavor was concentrated and delicious.
Marinate the chicken breast with minced curry roux. If you add sake and soy sauce to finish, they give a subtle flavor that suits Japanese tastes. Just add a small amount of water too smooth the texture out if it becomes too thick. I used a brand of curry roux called "Nidan Juku Curry (Sweet)".