Wash the cucumbers thoroughly under running water. Slice them thinly using a sharp knife or a mandoline for even thickness. This helps the cucumbers absorb the dressing better.

Julienne or grate the carrots and slice the red bell pepper into thin strips. Chop the green onions and cilantro. Combine all the vegetables in a large mixing bowl.

In a separate mixing bowl, whisk together the soy sauce, rice vinegar, sesame oil, sugar, minced garlic, grated ginger, and chili flakes until the sugar is dissolved. This dressing will provide a balance of salty, sweet, and tangy flavors.

Pour the dressing over the mixed vegetables in the large bowl. Toss gently to coat all the ingredients evenly. Allow the salad to sit for about 5 minutes to let the flavors meld.

Before serving, sprinkle the toasted sesame seeds over the top for added crunch and flavor. Serve chilled or at room temperature.