First, cut the tofu into slices. My slices were around 1 1/2 cm thick, and I ended up with 7 slices in total (but 6 slices would have actually been easier to portion out!). Press any excess liquid out of the tofu - if you don't have a tofu press, you can just lay the slices inside a folded (clean!) tea towel, place a baking tray on top, then a large pan full of water. The weight will squeeze the tofu, helping it to dry out. Leave for 10 minutes or so while you prepare the remaining ingredients.
In a small bowl, combine the flour with the curry powder and a good pinch of salt and pepper. Add the water, and mix thoroughly to give a smooth batter. You can add a little more flour or a dash more water to adjust the consistency - it needs to cling to the tofu, so should be fairly liquid, but not overly runny.
Place the breadcrumbs in another small bowl.
When the tofu has been pressed, dip each piece into the batter, and allow any excess to drip off. Then coat the tofu in the breadcrumbs. Place all of the slices on an oiled baking tray, and bake at 190°C (Gas Mark 5 / 375°F) for around 30-40 minutes, or until crisped up to your liking.
While the tofu is baking, prepare the katsu curry sauce. Heat a dash of oil in a large frying pan, and add the finely diced onion and carrot. Cook for 5 minutes, until the onion is fairly soft. Add the garlic and spices, and cook for 2 more minutes, before adding the remaining ingredients. Bring to a gentle simmer, and cook for another 15 minutes or so, until the carrot is completely soft.
Remove the bay leaf from the sauce, and blend until it reaches your desired consistency (I used a hand blender).
Serve the crispy tofu with the katsu curry sauce, and your choice of side dishes (I had rice and boiled edamame).