Preheat the oven to 375°F (190°C).
Slice the chicken breasts in half lengthwise so the pieces are about 1/4 inch thick.
Arrange the chicken on a large sheet pan.
Add the sliced red onion, minced garlic, black olives, Manzanilla olives, capers, artichoke hearts, and cherry tomatoes around and over the chicken.
Sprinkle crumbled feta cheese over the ingredients.
Drizzle everything with olive oil and season with salt, black pepper, and dried oregano.
Pour the non-alcoholic white cooking broth or chicken broth into the pan.
Bake for about 25 minutes until the chicken reaches an internal temperature of 165°F and the onions are soft and lightly caramelized while the tomatoes become roasted and juicy.
Serve the Mediterranean Chicken with Olives, Tomatoes and Artichoke Hearts warm directly from the pan.