Heat oil in a large pot over medium heat. Add ginger, garlic, and onions, and cook for 5 minutes until the onions are soft. Add carrots, and cook for another 5 minutes.
Add the vegetable stock, soy sauce, and ketchup to the pot and bring it to a boil. Reduce to a simmer, add Japanese curry mix, and stir until dissolved. Simmer for 5-10 minutes or until it thickens to your liking.
Katsu
Prepare a breading station by setting up three shallow bowls. In one bowl, add flour; in the second, add eggs; and in the third, add panko breadcrumbs.
Cover aubergine slices in flour, shaking off any excess; dip into egg, then press into panko breadcrumbs until evenly coated.
Heat about 1 inch of oil to 350°F. Place 1-2 slices of aubergine in the hot oil, and fry until golden brown, 3-4 minutes per side. Transfer to a wire rack to drain excess oil. Serve immediately with cooked rice, curry, and a side of tonkatsu sauce.
Notes
Storage: Keep eggplant and curry in separate containers. Store them in the refrigerator for up to three days.