Place each chicken breast on a cutting board, flat side down. Put the palm of your non-cutting hand on the top of the breast, and, using a very sharp knife, slowly cut horizontally through the breast, starting with cutting into the long, thick side. You should get 4 approximately equal slices of chicken. If some breasts are smaller, you do not need to cut them.
Place plastic wrap on the top of each chicken breast, and pound with a mallet or cup on the cutting board. The goal is to get the chicken flat and thin about 1/2-inch to 1-inch thickness.
In a large mixing bowl, combine Greek yogurt, salt, ginger, garlic, paprika, cumin and lemon juice. Add each chicken one at a time to the bowl and coat with the mixture. Place on a plate and repeat for all chicken breasts.
Cover and refrigerate 1 hour - marinating longer is okay too.
Remove chicken from the refrigerator 25 minutes prior to cooking so it is room temperature prior to cooking.
Preheat oven to 400 F. Using a roasting pan or large glass baking dish, arrange chicken in a single layer nestling lemon halves in between.
Roast chicken 25 minutes. Remove chicken from the oven and garnish with cilantro.
Switch the oven to high broil. Place chicken under the broiler 5-6 minutes to blacken the edges a bit. Remove and serve!