Cook the noodles according to package directions. Drain and set aside.
While the noodles are cooking, whisk together the tahini, soy sauce, rice vinegar, sesame oil, honey or maple syrup, minced garlic, and grated ginger (if using) in a medium bowl.
Add the hot water or a few tablespoons of the pasta water to the sauce and whisk until smooth and creamy. If the sauce is too thick, add a little more water until it reaches your desired consistency.
Add the cooked noodles to the bowl with the sauce and toss until thoroughly coated.
Serve immediately, garnished with toasted sesame seeds and chopped green onions.
