In a medium bowl, whisk together the peanut butter, lime juice, soy sauce, toasted sesame oil, maple syrup, and rice vinegar until smooth. Add the minced garlic, grated ginger, chili garlic sauce, and sea salt, stirring well to combine. Taste the sauce and add the water a tablespoon at a time until you reach a pourable consistency—it should coat the back of a spoon but still flow easily. I like to make the sauce slightly thinner than I think I need it, since the noodles will absorb some of the liquid as the salad sits.

Bring a large pot of water to a boil and cook the udon noodles according to package instructions (typically 5 minutes). Drain the noodles in a colander, then rinse thoroughly with cold water, stirring gently with your fingers to separate any clumps. This stops the cooking and prevents the noodles from becoming mushy. Let them drain well so excess water doesn't dilute the sauce.

While the noodles cook, spiralize the English cucumbers into thin noodle-like strands and set aside. Thinly slice the scallions, keeping the white and green parts separate for layering if desired, and roughly chop the fresh cilantro. This mise en place ensures everything is ready to assemble quickly once the noodles are chilled.

Place the cooled cooked noodles from Step 2 in a large serving bowl and pour about 1/3 cup of the peanut sauce from Step 1 over them, tossing gently to coat evenly. Add the spiralized cucumbers from Step 3, most of the sliced scallions, and the chopped cilantro, then toss again until everything is well combined. I always reserve some scallions and cilantro for garnish—it keeps the salad looking fresh and vibrant right up to serving.

Drizzle the remaining peanut sauce from Step 1 over the salad and toss lightly, adding a pinch more salt if needed. Transfer to individual bowls or a platter, then top with the roasted crushed peanuts, toasted sesame seeds, and reserved scallions and cilantro. Serve immediately while the noodles are still cool and the vegetables are crisp.