1. Prepare the Chicken for Grilling: Pat the chicken breasts dry with paper towels. In a small bowl, combine 1 tablespoon of olive oil, 1 teaspoon dried oregano, 1/2 teaspoon garlic powder, 1/4 teaspoon salt, and 1/8 teaspoon black pepper. Rub this mixture evenly over both sides of the chicken breasts. This seasoning will create a flavorful crust when grilled.

2. Grill the Chicken to Perfection: Preheat your grill (or grill pan) to medium-high heat. Once hot, place the seasoned chicken breasts on the grill. Cook for 5-6 minutes per side, or until the internal temperature reaches 165 F (74 C) and the chicken is no longer pink in the center. You’ll see nice grill marks forming on the outside. Remove from heat and let rest on a cutting board for 5 minutes. This resting period helps the chicken stay juicy.

3. Dice the Vegetables for the Salad: While the chicken is grilling and resting, prepare your vegetables. Dice the cucumber and tomatoes into bite-sized pieces. Thinly slice the red onion. Halve the pitted Kalamata olives. Place all these prepared vegetables into a large salad bowl.

4. Whisk Together the Simple Dressing: In a small bowl or jar, combine 1/4 cup extra virgin olive oil, 2 tablespoons red wine vinegar, 1 teaspoon Dijon mustard, 1/2 teaspoon dried oregano, and salt and black pepper to taste. Whisk vigorously until the dressing is well combined and slightly emulsified. The Dijon mustard helps to bind the dressing.

5. Slice the Grilled Chicken: After resting, slice the grilled chicken breasts against the grain into 1/2-inch thick strips or dice them into cubes, depending on your preference. Cutting against the grain ensures tender pieces of chicken.

6. Assemble and Serve the Salad: Add the sliced or diced grilled chicken to the bowl with the prepared vegetables. Crumble the feta cheese over the top. Pour the dressing over the entire salad. Toss gently to combine all the ingredients, ensuring everything is evenly coated with the dressing. Garnish with fresh parsley if desired, and serve immediately.