In a large skillet heat 1 tablespoon of the oil over medium heat. Lightly sprinkle chicken tenders with salt and pepper. Cook chicken in hot oil for 8 to 10 minutes or until no longer pink, turning once halfway through cooking time.
For vinaigrette, in a screw-top jar combine the remaining 4 tablespoons oil, the vinegar, thyme, sugar, 1/4 teaspoon salt, and 1/4 teaspoon pepper; cover and shake to combine.
On four dinner plates, arrange chicken, cucumber ribbons, sliced tomatoes, and olives. If desired, sprinkle with feta cheese. Drizzle vinaigrette over salads.