In a medium bowl, combine the chicken, salt, pepper, baking soda, and tapioca flour. Toss until well combined.
Heat the oil in a large, deep skillet or wok over medium-high heat. Add the chicken in a single layer, working in batches and adding more oil as needed, and cook until golden brown on each side and cooked through, about 3 minutes per side. Using a slotted spoon, transfer the cooked chicken to a clean plate and set aside.
Add more oil to the pan if it seems dry. Add the onions, white parts of the green onion, carrots, and cabbage. Cook, stirring, until the veggies are slightly tender, about 3 minutes.
Add the prepared sauce and let simmer, tossing occasionally until reduced slightly, about 2 minutes. Add the reserved chicken and continue to cook, stirring occasionally, until the sauce has thickened, 3 to 4 minutes.
Add the green parts of the green onion and toss once more. To serve, divide among bowls and top with chopped peanuts.