Make the dressing: In a large bowl, whisk to combine ⅓ cup unseasoned rice vinegar, 1 tablespoon low-sodium soy sauce, 2 tablespoons sugar, 1 tablespoon spicy brown mustard, and the leaves of 6 small sprigs of thyme. Finely chop ½ a serrano chile and stir in. Working slowly, whisk in ⅔ cup roasted peanut oil until thick and emulsified. Season the dressing with salt and pepper.
Prep the salad: Start slicing and adding everything to the bowl: Thinly slice 3 scallions and 8 oz napa cabbage. De-stem 1 8-oz bunch of curly kale and tear it into bite-sized pieces, adding to the bowl as you go. Pluck the leaves of a big handful of mint and cilantro, adding to the bowl. Finally, smash 1 cup roasted salted peanuts and add about ⅔ of them in. Toss everything very well, seasoning with salt and pepper, and working until everything is well coated in the dressing. Add more vinegar as needed until it tastes really bright and nice. Lastly, sprinkle over 2 ounces grated Parmigiano Reggiano and toss once more.
Serve: Serve, sprinkled with more parm and peanuts, piled high as can be on a plate!
