Add 4 tablespoons olive oil along with chicken, onion, garlic and bay leaves to a slow cooker. Set the heat to High. Season with salt and pepper, stir, and cover. Cook for about 1 hour, stirring occasionally.
Add the carrots, celery, potatoes, thyme, sage, and white wine. Season with salt and pepper, stir, and cover. Cook for about 2½ hours, stirring occasionally, until vegetables are fork tender.
Reduce the heat to Low. Add the broth and peas, cover and cook for about 1½ hours. Season to taste with salt and pepper, and serve.