Prepare the water and cucumbers.
Bring a large pot of salted water to a rolling boil.
While it heats, peel the cucumbers, slice them in half lengthwise, and use a spoon to scoop out the seeds.
Shred the cucumber using a box grater or by cutting it into thin matchsticks.
Set aside.
Cook the noodles.
Add the noodles or pasta to the boiling water and cook according to package directions until al dente—tender but not mushy.
Mix the sauce.
While the noodles are cooking, combine the tahini or peanut butter, sesame oil, sugar, soy sauce, optional ginger, vinegar, hot sauce, and black pepper in a large mixing bowl.
Whisk until smooth.
Thin the sauce and add cucumbers. Gradually whisk in 1/4 cup (960 ml) of hot water to the sauce until it reaches the consistency of heavy cream.
Add more water, one tablespoon at a time, if it's still too thick.
Stir in the shredded cucumbers.
Combine and serve.
Once the noodles are cooked, drain them immediately and rinse under cold running water to stop the cooking process and cool them down.
Drain thoroughly.
Add the cooled noodles to the bowl with the sauce and cucumbers.
Toss everything together until the noodles are well-coated.
Taste and adjust seasoning with more salt or soy sauce if needed.
Garnish generously with minced scallions and serve immediately.
Variation: Cold Fiery Noodles
For a lighter, spicier version, omit the tahini/peanut butter from the sauce. Increase the rice vinegar to 2 tablespoons and whisk in 1/4 cup (960 ml) of a neutral oil like grapeseed or peanut oil.
Add 1/2 cup (480 ml) of bean sprouts, a handful of thinly sliced radishes, and at least 1 teaspoon (5 ml / 0.2 fl oz) of chili paste along with the cucumbers.
Garnish with scallions, chopped cilantro, and crushed peanuts.
Don't skip rinsing the noodles in cold water after cooking. This stops them from overcooking, removes excess starch, and prevents them from clumping together.
