Make a batch of wok salt—it goes with everything: In a wok or a frying pan (large enough to hold the ingredients spread in an even layer) over medium heat, combine the white peppercorns, Sichuan peppercorns and black peppercorns and toast, tossing or stirring frequently, until fragrant, about 2 minutes. If you see or smell anything more than a wisp of smoke, it’s probably best to start over. Add salt and smash in the mortar or grind in the spice grinder, working in batches if necessary. Leave the Wok Salt coarse, like cracked pepper. Transfer to an airtight container; store in a cool, dry place; and use within a month or two.
In a small bowl, combine the jalapeño and soy sauce and let marinate.
Separate the squid body and tentacles by cutting right below the eyes. Squeeze out and discard the hard beak from the tentacles; reserve the tentacles. Holding the body, pull out and discard the head, then the guts, ink sac, and clear skeleton. Working from the cut end of the body, grasp the thin speckled skin, peel toward the tip, and discard. Rinse well. Quarter the bodies lengthwise, then cut in half crosswise to get 8 pieces from each body.
Put 1 cup of the cornstarch in a large bowl. In a separate large bowl, make a wet batter by whisking together the club soda, glutinous rice flour, rice flour, wok salt, and remaining 1/3 cup cornstarch.
To make the vinaigrette: Warm a small frying pan over medium heat. Add the 1 tsp. neutral oil and let it heat up for a few seconds. Add the green onion and sauté until softened, about 1 minute. Transfer to a large bowl, add the pecan oil and vinegar, and whisk to combine. Set aside.
Fill a wok or a Dutch oven with the 1 1⁄2 qt. neutral oil and secure a deep-fry thermometer on the side. Set over medium-high heat and warm the oil to 375° F, being careful to maintain this temperature as you fry.
Preheat the oven to 200°F. Fit a roasting wire rack over a baking sheet.
Toss the squid in the plain cornstarch until evenly coated. Tap off the excess and then drop the squid into the wet batter, making sure every crevice is coated. Transfer to a colander and shake the excess batter back into the bowl.
A small handful at a time, slide the squid into the oil and fry, stirring occasionally to break up any pieces that stick together, until light golden brown, crisp, and cooked through, about 2 minutes. Transfer to the prepared rack, season generously with more wok salt, and keep warm in the oven as you fry the rest.
Whisk the vinaigrette again. Add the parsley, cilantro, and the jalapeño and soy sauce that's been marinating. Season with kosher salt and toss to combine. Add the squid and toss again. Serve while the squid is hot with additional wok salt on the side.