Slice the cucumbers into thin rounds, about 1/8-inch thick. For a decorative touch, you can use a mandoline or run a fork along the sides before slicing.
Thinly slice the red onion into half-moons. If desired, soak in ice water for 10 minutes to reduce sharpness, then drain and pat dry.
In a large bowl, combine the sliced cucumbers, red onion, and minced jalapeño.
In a small bowl, whisk together the fresh lime juice, olive oil, salt, and pepper until well combined. Add optional cumin, chili powder, or honey if using.
Pour the dressing over the vegetables and toss gently to coat evenly.
Add the chopped cilantro and give the salad a final light toss. If using optional ingredients like avocado or tomatoes, fold them in gently now.
Taste and adjust seasoning as needed.
Serve immediately or refrigerate for 15-30 minutes to allow flavors to develop. Sprinkle with crumbled cheese just before serving if desired.
