Heat the oil in a large pan over medium-high heat, add the beef and brown on all sides before setting aside.
Add the onion to the pan and cook until tender, about 5 minutes.
Add the garlic and ginger and cook until fragrant, about a minute.
Add the beef, carrots, potatoes, broth, apple, honey, soy sauce, ketchup, curry roux (see below), bring to a boil, reduce the heat and simmer until the carrots and potatoes are tender, about 20 minutes.
Melt the butter in a pan over medium heat and simmer until it just starts to turn a light golden brown.
Sprinkle in the flour and curry powder, and simmer, whisking, until it turns a golden brown and smells nutty, before turning off the heat.
