Slow Cooker Greek Lemon Chicken Soup

2 Tbls Olive Oil 1 Larger Sweet Yellow Onion Diced 3 Stalks Celery Diced 2 Large Carrots Diced 3 Large Garlic Cloves Finely Chopped 1 Tbls Salt 1 Tbls Black Pepper 1lb Boneless Skinless Chicken Breast 2 Cups Water 4 Cups Chicken Stock 1 Cup Chicken Bone Broth 4 Bay Leaves 1 Tbls Dried Oregano…