Marinate the chicken in olive oil, salt, pepper, and oregano for 30 minutes up to overnight. Bake at 350 for 20-30 minutes or until cooked through completely
Add diced tomatoes to a collander and sprinkle with salt and cover it with a paper towel to draw water out of them. In a bowl of ice water, add sliced onions. Let both bowls sit for 15 minutes
Cook noodles according to packaging
In a large bowl, add diced chicken, drained tomatoes, sliced onions, noodles, olives, cucumber, bell pepper, feta, and avocado
In a small bowl, mix olive oil, salt, pepper, and oregano. Pour and gently mix over pasta salad
Refrigerate and serve cold