Whisk together your olive oil, red wine vinegar, sea salt, black pepper, garlic powder and red pepper flakes and store in a ramekin or small bowl.
Minced basil, cilantro and mint and set aside.
Cut chicken thighs in 1 ½”-inch bite-sized pieces and place in a bowl. Drizzle with about 1/3 of the marinade and allow to come closer to room temperature for about 25-20 minutes prior to grilling. While chicken is marinating, soak your skewers in water (if using wooden).
Add minced herbs to the remaining 2/3 of the marinade to be served with your skewers.
Thread each skewer so that the chicken pieces are close to each other without gaps.
Heat a grill pan to high heat and when very hot, carefully place each skewer on the pan and do not move once in so that they each get good grill lines on them. Allow to sear about 5 minutes per side.
While chicken is grilling, arrange mixed lettuce on a large serving plate. This is where your skewers will be served. Set marinade on the plate. Add mixed olives to the plate.
When your chicken is done grilling, carefully remove them from the grill pan and set on top of the mixed lettuce.
Serve between 4 (a skewer per person with 1 extra), storing any leftovers in the fridge for up to 3 days.