I have made at home several recipes from NHK World
https://www3.nhk.or.jp/nhkworld/en/food/
Learn some basics of Japanese Language here:
https://www.nhk.or.jp/lesson/english/learn/list/1.html
And Travel & Culture
https://www3.nhk.or.jp/nhkworld/en/culture/
Peter (Varacan or Baracan, I’m not sure how to spell his last name) is a British guy who host some of the NHK World food, and culture videos. Many of them can also be found on YouTube generally with the Japanology or Begin Japanology label.
I have found Japanese style croquettes to be quite tasty.
和風コロッケ・レシピ (wafū korokke reshipi) Japanese style croquettes recipe.
There are many variations of ingredients, and methods making them.
https://www3.nhk.or.jp/nhkworld/en/food/recipe/kyou_21700.html
Several of these recipes recommend Bulldog brand Tonkatsu sauce, or Tankatsu mixed with some ketchup. Which is good.
However - The first Japanese Korokke recipe I made gave this recipe for the sauce.
I found it to be pretty good. Good on other foods too, And a good alternate to Tonkatsu, now and again.
2T Mayonnaise
1T Whole grain mustard
1T Apple cider vinegar
1/2 t Sugar.
The recipe for the Korokke was:
4 Medium potatoes, red or yellow
1/4 lb ground pork
1 Medium onion, minced
1/4 t salt
1/4 t white pepper
1T Soy sauce
1T Mirin
1/4 t Brown sugar
Unfortunately, I seem to have not written down the website or video where I found it.
コロッケソースおすすめ ( korokkesōsu osusume) Croquette sauce Recommended
Journeys in Japan
Okayama: The profound spirit of the rocks