Make the noodles. Cook the noodles according to package instructions. After you drain them once, rinse with cool water and drain them well again. Set aside.: As the pot simmers you'll notice a faint wheaty aroma rising from the water and the noodles will begin to swell and soften, showing a tender, glossy surface; when you drain them the initial steam will carry that warm scent, and rinsing with cool water immediately stops the cooking, firms the texture, and removes surface starch so the soba noodles do not clump. Why this matters, I often ask myself, because overcooked noodles go mushy and cannot hold the dressing, while undercooked noodles taste chalky; aim for just tender. A common mistake is leaving the noodles in the hot water too long, which makes them limp and unable to carry the dressing properly, so rinse promptly and drain thoroughly to remove excess water so the final bowl is not watery.
Make the dressing. While the noodles cook, put all the ingredients for the dressing in a food processor and run until smooth.: When you pulse the ingredients together you'll see the mixture transform from chunky bits to a glossy emulsion, and the scent will lift as the ginger and garlic release aromatic oils; a perfectly blended dressing should be creamy and pourable, clinging to a spoon with slight ribboning. This technique matters because a smooth emulsion coats the noodles evenly, giving every forkful balanced flavor. A frequent error is under-blending, which leaves gritty lumps and uneven seasoning, so blend until there are no visible pieces and add the measured water to reach the right viscosity, tasting for salt and acidity before stopping.
Assemble the dish. Place the cooked noodles, carrots, cabbage, and scallions in a large salad bowl and pour the dressing over the noodles and vegetables. Use two forks or tongs to gently toss. Sprinkle with the cilantro and mint and toss again. Top with the cashews just before serving.: At this moment you'll hear a soft rustle as the veggies and soba noodles meet, and the bright citrus and nutty aromas will lift from the bowl as the dressing hits the warm noodles; toss gently using two forks or tongs so the dressing coats without bruising the herbs. This gentle toss retains the crispness of the carrots and red cabbage , while allowing the soba noodles to pick up flavor. The reason we add the dressing now is to ensure each strand is evenly coated, preventing separate pockets of dryness. Avoid vigorously whipping the mixture, which can break delicate noodles and make the veggies soggy.
Use two forks or tongs to gently toss. Sprinkle with the cilantro and mint and toss again.: When you fold in the herbs you'll notice small bursts of green that change the bowl's scent and palette instantly; the cilantro and mint leaves should remain bright, not wilted, signaling that you added them at the right time. This matters because adding herbs too early muddies their flavor and texture, while adding them too late can look like an afterthought. A typical mistake is chopping the herbs too finely, which causes them to lose texture and aroma, so tear or leave them lightly whole to maintain freshness.
Top with the cashews just before serving.: The final sprinkle of chopped roasted cashews provides a sharp textural contrast and releases a toasty scent that elevates each bite; adding them at the last moment preserves their crunch, ensuring you get satisfying bites against the soft noodles. This step matters because the contrast of textures is key to the eating experience, and stale or soggy nuts will flatten the profile. Do not mix them in too early or they will absorb moisture and lose their crispness, so reserve them until plating and scatter them evenly for balance.