I have a recipe for homemade curry roux, the stuff in the picture, to share as well, though I figure I'll go for the simple way first. In short, this was the first thing I learned how to make on my own involving an oven/stove and, as a result, is pretty much a comfort food for me. It's my go-to for when I come home after a long day and don't feel up to making anything yet still need to get some food in me.
If you're not familiar with this type of curry, especially if you get a box lacking English/can't understand Japanese, it might seem intimidating at first. That or the roux might make you think of it as a weird smelling chocolate(one of my cousin's impressions of it). Don't fret though, it's pretty straightforward.
While you can use any veggies that sound good, I tend to go with onions, carrots, potatoes, and tofu. Using a small pot, chop enough to fill it halfway. Typically one carrot, one potato, half a cube of tofu, and quarter of an onion or one scallion stalk. Fill the pot with enough water to cover the veggies then boil it over medium heat for the amount of time it takes for a rice cooker to cook two cups of rice(or until the potato and carrots are soft... don't you love how vague my instructions tend to be? Sorry, I rarely cook with timers and eyeball most measurements).
For a little added/personal taste, you can also choose to fry the onions/other veggies before adding them to the pot, though since this is my definitive lazy meal, I tend not to.
Once the veggies are ready, add the roux half a bar at a time, I find that a small pot filled roughly to the top takes 2 and a half bars to get it just right though this may vary by the size of your pot. Mix each until it's fully dissolved and keep adding until the curry is a thick, almost batter-like, paste.
Congrats! You've got curry! Serve over fresh rice or udon and dig in!
