Season chicken breasts with half of the salt and black pepper on both sides.
Grill or pan-sear chicken over medium-high heat for approximately 6 minutes per side until the internal temperature reaches 165 degrees Fahrenheit.
Remove chicken from heat and let rest for 5 minutes before slicing into 1/2-inch strips.
In a small mixing bowl, whisk together the Greek yogurt, lime juice, chopped cilantro, garlic powder, and the remaining salt and pepper to create the dressing.
In a large assembly bowl, combine the mixed salad greens, halved cherry tomatoes, and sliced red onion.
Top the salad base with the warm chicken strips and the avocado slices.
Drizzle the skinny creamy dressing over the salad and serve immediately.