Cook any proteins you are using first, since those will take longer than the rest of the noodles. You can simply season with salt and pepper, as you'll double the sauce recipe to coat the protein in sauce.
Cook the noodles in a small saucepan or small pot according to the package directions, reserving at least 1 tablespoon (15 milliliters) of noodle water.
Make the sauce while the noodles are cooking. In a bowl big enough to fit the noodles, combine the peanut butter, vinegar, Sichuan chili crisp oil, sesame oil, and soy sauce.
Add 1 tablespoon (15 milliliters) of the hot noodle water and mix. Don't worry about it being completely smooth, as it will come together more when you add the noodles.
Chop the scallions (if using) and set aside.
Combine the cooked noodles and sauce by using tongs or chopsticks to transfer the noodles directly from the pan to the bowl (save yourself having to wash a colander!). If it's easier, you can drain with a colander.
Use chopsticks to mix the noodles and any cooked proteins (if using) with the sauce until it's fully combined.
Taste and add more sauce to your preference- (Jen personally adds more vinegar and chili oil than the recipe calls for). Find the ratios that work best for you and jot them down for next time!
Top with your chosen garnishes and add-ons (if using) and enjoy!