Japanese curry

Japanese curry: my favourite dish. It's time to attempt making it.

I got a pack of the ready-made sauce cubes from the Japan Centre near Piccadilly Circus, but unfortunately, all the instructions are in Japanese. Here's what I could make of it:

Ingredients
200 g meat
300 g onion
100 g carrot
150 g potato
2 tablespoons vegetable oil
700 ml water
94 g of "melty" curry roux (i.e., the contents of the pack)

Here's what I actually used:
400 g minced pork
300 g (before peeling) finely sliced onion
100 g (before peeling) sliced carrot
1 can (325 g net) of new potatoes, diced
2 tablespoons vegetable oil
> 600 ml water
94 g of "melty" curry roux (i.e., the contents of the pack)

Directions
On a medium fire, stir-fry the ingredients in a thick pot thoroughly and add water (5-10 minutes).

Cover loosely on a low to medium fire for about 20 minutes.

Turn off the fire, break the roux into the pot, and make sure it melts thoroughly.

Stir and simmer on low fire for about 5 minutes.

My interpretation:
In a big pot, heat the oil on a medium fire and throw in first the onions, then the meat and then the rest of the vegetables (the canned potatoes are actually almost cooked, so I added them in later) until the meat is cooked and the onions are starting to brown. Add the water, bring to boil and reduce heat to simmer while loosely covered until vegetables are soft (it definitely took more than 20 minutes).

Hint on the water: the exact amount of water will be prescribed on the pack of roux being used (in the most likely scenario that all the directions are in Japanese, look for 水 = water). However, it might be a good idea to actually use a bit less in case it comes out a bit thin. If it's too thick, it can be diluted by adding a bit more hot water; but if it's too thin, it's more difficult to rescue.

When the vegetables are ready, take off the fire and add the roux according to instructions (e.g., break it in cubes) and stir until completely mixed. Simmer again while stirring for about 5 minutes to make sure everything is thoroughly stirred. This would be the time to top up with water, if necessary, to achieve desired consistency.

Serve with rice and boiled egg.