Preheat oven to 350 degrees.
Lightly coat a large baking dish with olive oil. Place spinach in the baking dish and sprinkle with salt and pepper; add chicken broth and garlic. Sprinkle chicken with Greek seasoning and add salt and pepper, if desired.
Arrange chicken on top of spinach and evenly top with roasted red peppers, artichoke hearts and Feta (if desired). Cover the baking dish with foil wrap and bake for 25 to 30 minutes.
Uncover and bake for 10 minutes longer or until chicken has browned slightly and is cooked through.