While you're slicing the cucumber, prepare all your aromatics and seasonings so they're ready to go. Finely mince the 2 garlic cloves and grate the fresh ginger. Measure out the soy sauce, toasted sesame oil, rice vinegar, sugar, fish sauce, and MSG (if using) into a small bowl—this is your dressing base. Having everything prepped means your salad will come together quickly without any delays once the cucumber releases its liquid.
In a small dry skillet over medium heat, lightly toast the sesame seeds for 1-2 minutes, stirring frequently, until fragrant and golden. Transfer to a plate to cool. Meanwhile, using a mandoline, thinly slice the English cucumber into uniform 1/8-inch rounds—this creates that satisfying thin, delicate texture that makes this salad work so well. I like to place a towel under my mandoline to catch any water and keep my work surface dry.
Place the sliced cucumbers in a large bowl and sprinkle evenly with the kosher salt. Toss gently to distribute the salt throughout. Let the cucumbers sit for 10 minutes—the salt draws out excess water that would otherwise make the salad watery. After 10 minutes, drain the accumulated liquid by pouring the cucumbers into a colander or carefully tilting the bowl and pressing gently with a paper towel to remove excess moisture.
Return the drained cucumbers to the bowl. Pour the prepared dressing mixture from Step 1 (with the garlic, ginger, soy sauce, sesame oil, vinegar, sugar, fish sauce, and MSG) directly over the cucumbers and toss gently to coat everything evenly. The warm aromatics will begin to infuse the cucumber slices with incredible flavor. For the best result, let this sit for just 2-3 minutes before adding the final components—this allows the flavors to start melding.
Thinly slice the green onions and add them to the bowl along with the toasted sesame seeds from Step 2 and the chili crisp. Toss everything together gently but thoroughly, making sure the chili crisp is distributed evenly throughout. I always use Lao Gan Ma chili crisp because it has the perfect balance of heat, oil, and crispy bits that give this salad its signature texture and appeal. Taste and adjust seasoning if needed—you may want a touch more soy sauce or chili crisp depending on your preference.