In a large bowl, mix together the olive oil, lemon juice, Greek seasoning, and fresh dill.
Cut the chicken tenders into 1-inch pieces and place in the marinade. Mix the chicken and cover to marinate. Refrigerate for at least one hour or up to 12 hours, but no longer.
While chicken marintes, soak wooden skewers in water.
Once you are ready to cook the chicken; remove the chicken from the refrigerator.
Preheat the grill to 400 degrees Fahrenheit.
Begin to skewer chicken alternating with a slice of red onion and lemon. Repeat until all chicken and onions are skewered.
Before grilling, clean grill and spray the grates with non-stick cooking spray. Reduce the heat too low. Place skewers on the grill. Grill for 5 minutes, then flip and grill for an additional 5 minutes. Internal temperature of chicken should read 165 degrees Fareneheit.