1.First make the curry paste In a frying-pan, add butter and flour. Stir to combine over low heat.
2. When it starts to be liquid, then add curry powder. Cook and stir for a few minutes and remove from the heat. Transfer into a small bowl and set aside.
3. In a big cooking pot, heat 1 to 2 tbsp vegetable oil, and fry the garlic until fragrant. Then add onions, and cook gently over low heat until browned (about 20~30min).
4. Add water, soy sauce, mirin and apricot jam. Bring to a boil.
5. Add a ladleful or two of the stock from step #4 into the curry paste bowl from #2. Mix well. Then gradually add it all into the curry paste bowl. Mix until smooth, using an egg whisk if necessary.
6. Add kosher salt and brown sugar to adjust the taste. Mix well. The curry sauce is done!
7.Now make the katsu Stab the pork with a fork. Season the pork pieces with salt and pepper, dust with flour. Then dip them in the beaten egg+water mixture. Finally coat the pork with panko bread crumbs, evenly, pressing down gently. Both sides should be completely coated.
8. In a frying pan, heat up the cooking oil over medium high heat until it reaches 180℃. Fry the pork until both sides are golden brown, turning them in the oil once or twice. Drain on a plate covered with paper towels.
9. Slice the cooked tonkatsu into strips and place over the rice, then pour the curry sauce.
Garnish with beni shoga over the rice if you like!