Bring a large pot of water to a boil, add salt, then break spaghetti noodles in half and add to the boiling water.
Stir, let it come to a boil again, then cook until noodles are tender but still have a little bite, for us this was about 18 minutes for Fiber Gourmet Spaghetti but I would start checking sooner than that.
While pasta water is coming to a boil, combine unseasoned rice vinegar, soy sauce, peanut oil, Chili Garlic Paste, minced ginger, sesame oil, and Golden Monkfruit Sweetener to make the flavorful sauce.
While the noodles are cooking, chop the chicken into same-size pieces about 1/2 inch square, and combine chicken with about 1/3 cup of the sauce mixture to let it soak up the flavor of the sauce.
Wash cilantro, spin dry or dry with paper towels, and chop. Slice the green onions. (If you're not a cilantro fan I would just use a bit more sliced green onion.)
When noodles are cooked but still al dente, drain them into a colander placed in the sink.
Put noodles back into pan you cooked them in and add the diced chicken that was marinating in the sauce.
Pour the rest of the sauce mixture over chicken and noodles, then toss well enough that noodles and chicken are well-coated with the sauce mixture.
Add chopped green onions (and chopped cilantro if using) and toss just enough to combine.
Sprinkle with toasted sesame seeds if using, and serve right away.