Vegan Katsu Curry Japanese Curry Sauce

While the original was made with pork cutlet, I’ve developed a process to turn a block of firm tofu into a delicious plant-based meat substitute. The Tofu Katsu ends up crispy on the outside and meaty and flavorful on the inside. Smothered with a homemade Japanese curry sauce, this vegan Katsu Curry is packed with enough flavor to satisfy even the most skeptical meat-eater.

Why This Recipe Works?

The curry sauce is thickened with a mixture of pureed vegetables and aromatics. This eliminates the need for making a flour and butter roux. Baking soda raises the pH of the vegetable puree, which helps it caramelize in about ⅓ of the time it would typically take. A small amount of cocoa powder adds an earthy roasted flavor to the curry, making it taste like it’s been simmering away for hours. I like to add a colorful array of vegetables to my Katsu Curry, and flash frying them with the oil for the katsu makes it easy. It also locks in their vibrant color while contributing additional textures and tastes that keep the Katsu Curry from getting boring.

Ingredients for Vegan Katsu Curry

Tofu katsu - Follow the instructions in my tofu katsu recipe to make the vegan katsu. I’ve included cues in this recipe for when you should start each part of the process to finish the katsu around the same time as the sauce and vegetables. Japanese short-grain rice - We use short-grain rice in Japan which is stickier and sweeter than long-grain rice. I have a post explaining everything you need to know about Japanese short-grain rice, including how to select it and how to cook it. Vegetables - For the flash-fried veggies, I recommend using a colorful variety of vegetables that will hold up well to the high temperatures involved in frying. Root vegetables like carrots, parsnips, and burdock are all excellent options, and I also like doing green beans and romano beans. I’ve used red and green peppers, orange kabocha, and purple Japanese eggplant for this one.

Ingredients for Katsu Curry Sauce

Aromatics - Onions, garlic, and ginger are the holy trinity of aromatics for Japanese curry, and these ingredients are caramelized to bring out their aroma and sweetness. Rather than cooking the sauce for hours to let these ingredients melt into the sauce, I puree them from the start to speed things up. Carrot - I also like to add some pureed carrot, which adds natural sweetness to the curry. Baking soda - Baking soda is alkaline and will raise the pH of the vegetables in the curry base. This cuts the caramelization time for the mixture down to a third of what it would normally take. Japanese curry powder - Japanese curry powder is a blend of about 20 different spices. It differs from other types of curry powder because it includes Western herbs such as thyme and sage while also including East Asian spices such as star anise and mandarin peel. The most common pre-blended Japanese curry powder brand is S&B (make sure you get the powder in a can and not the instant roux in boxes). If you want to try making your own, I have a Japanese curry powder recipe. Vegetable stock - Japanese curry is usually made with meat-based broths, but vegetable stock works just as well when fortified with other umami-rich ingredients. I like using this vegetable dashi pack which makes it super easy to make a flavorful veggie stock. Soy sauce - Soy sauce is rich in amino acids, which bolsters the umami from the vegetable stock while acting as the primary source of salt for the curry sauce. Tomato paste - Tomatoes are a component of Japanese curry’s fruity flavor and sweetness. Since tomato paste is concentrated tomato pulp, it’s a time-saving addition that avoids having to peel and seed whole tomatoes and then boil the pulp down into a concentrate. Date syrup - One of the defining characteristics of Japanese-style curry is that it is much sweeter than curry from other regions of the world. This was likely due to the population’s unfamiliarity with spicy tastes when curry first appeared in Japan 150 years ago. The sweetness tames the spices, and ingredients like fruit and honey are a common addition to Japanese curry. Since it takes a while for the flavors of fruit to disappear into the curry, I prefer directly sweetening this quick curry sauce. Date syrup is my preferred option because it also adds a marvelous caramel flavor, but other vegan-friendly sweeteners like maple syrup or agave will work. Just make sure you adjust the quantity of sweetener to compensate for the differences in perceived sweetness (agave is much sweeter than date syrup). Cocoa powder - Kakushiaji (隠し味) is a Japanese word that literally means “hidden flavor,” and it’s used to reference an ingredient that’s added to a dish that enhances the dish without being obvious. Cocoa powder is the kakushiaji in this curry, providing a marvelous toasty flavor that makes the curry sauce taste like it’s been bubbling away for hours.

How to Make Vegan Katsu Curry

Giving the tofu a meaty texture requires planning ahead because you need to freeze and defrost the tofu. Then I press the tofu to remove the excess water, leaving behind a meaty soy protein. This gets seasoned with a mixture of Marmite and vegetable stock to infuse it with flavor. Then it’s battered and breaded with panko. Finally, it’s deep-fried until golden brown and crisp. I have a full explanation of the process in my Tofu Katsu recipe. I’m going to focus mainly on the vegan curry sauce to pour over the katsu in this recipe. To prep the vegetables for the Katsu Curry, make sure you dry them well with paper towels after washing them, or they will spatter when you fry them. I usually cut the peppers into segments and then use a knife to cut out the light-colored membranes and the core. Then you can cut them into thick strips. For the kabocha, I use a spoon to scoop out the seeds, and then I usually cut it in half to make it more manageable. Then you can slice it into ⅛-1/4-inch thick slices. Too thin, and they will burn. Too thick, and they will take forever to cook through. For the eggplant plant, I usually just cut them in half lengthwise, leaving the stem portion attached because it looks nicer, but this part is too tough to eat, so if you want to make it easier to eat, you can trim it off. Then you want to cut slits into the skin-side of the eggplant (about halfway through) ⅛-inch apart. This helps the eggplant cook through faster, which prevents the skin from getting dried out and leathery. Prepare a cooling rack by lining it with a few paper towels. You’ll also want to bread your tofu katsu at this time. For the curry sauce seasonings, add the vegetable stock, soy sauce, tomato paste, date syrup, cocoa powder, and potato starch to a bowl and whisk all of the ingredients together. For the curry sauce base, you want to puree the onion, carrot, garlic, and ginger. The easiest way is to peel and roughly chop the vegetables and then run them through a food processor or blender. Be sure to scrape down the sides of the bowl as many times as necessary to get a smooth puree. Another option is to use a rasp or daikon grater to grate the whole vegetables. The goal is to end up with a puree like smooth applesauce. Dump the pureed aromatics into a non-stick frying pan and mix in the baking soda. This raises the pH of the vegetables and significantly cuts the time required to caramelize them. Next, turn on the heat to medium-high and boil the mixture while stirring until the water has evaporated and the mixture thickens into a paste. This should take five to six minutes. Add the oil to the pan and mix it into the paste. Then you want to continue stirring the mixture for five to six minutes until the paste has become thick, glossy, and tan in color. Add about an inch of oil to a high-sided pot and start preheating it to 340°F (170°C). Once the onion puree has caramelized, add the curry powder and stir it into the paste. This toasts the curry powder and brings out its aromas, but be careful not to burn it. Next, add the curry sauce seasoning mixture to the pan and stir. Lower the heat to maintain a gentle simmer, and stir the curry occasionally while you fry the vegetables. The vegetables will take different amounts of time to cook, so I recommend doing them one at a time. The kabocha pumpkin will take the longest, so I usually start with that. Just lower it into the oil and fry it until the edges brown (for 2-3 minutes). Transfer to the prepared rack to drain. The peppers will take anywhere from thirty seconds to a minute, depending on how thick they are, and you’ll know they’re done when the shiny skins start to blister. Moderate heat will degrade the anthocyanins in eggplant skin, causing them to discolor and turn brown. By adding the eggplant skin-side down into the oil, the high temperature preserves the anthocyanins, which will leave your eggplant a vibrant shade of purple. You can flip them over after about half a minute and then fry them until they’re tender (another minute or so). Unlike the other vegetables, eggplant will soak up oil like a sponge, so drain them on the paper towels with the cut-side down. You may also want to pat them tops with additional paper towels to remove excess oil. Once all of your vegetables are done, you can fry the katsu. I recommend doing this at the last minute to ensure the katsu is extra crispy when you serve it. Drain the katsu on the prepared rack and then slice it up. To assemble the Katsu Curry, lay down a bed of cooked rice, and then arrange the katsu and fried vegetables on top. Finish the dish by pouring the Japanese curry sauce over half of the katsu and veggies. Serve your Katsu Curry as fast as possible, or your katsu will go soggy.