Step 1: Toss the cut asparagus with 1 teaspoon of olive oil and a small pinch of salt. Heat a cast-iron skillet over medium-high heat. Add the asparagus in a single layer and sear undisturbed for 2-3 minutes until charred on one side. Toss and cook 2 minutes more until tender-crisp. Remove from heat and let cool.
Step 2: In a large salad bowl, combine the sliced cucumber, halved cherry tomatoes, thinly sliced red onion, and halved Kalamata olives.
Step 3: In a separate small bowl or chess jar, combine the 1/4 cup extra-virgin olive oil, fresh lemon juice, minced garlic, dried oregano, sea salt, and black pepper. Whisk or shake vigorously until fully emulsified.
Step 4: Add the cooled charred asparagus to the large bowl with the other vegetables. Pour the dressing over the ingredients and toss gently to coat. Scatter the crumbled feta cheese over the top, give it one final gentle fold, and serve.