Heat oven to 350° F.
Heat oil in a large pan over medium-high heat. Use a pan that can be used on the stove stop and then placed in the oven. It needs to be at least a 5 qt pan. When the oil is hot brown the skin of each chicken thigh, then set aside on a plate.
Add the balsamic vinegar to the pan along with the onions. Sauté for about 5 minutes until the onion began to soften. Add dates olives, garlic, rosemary, thyme, black pepper to taste and salt. Sauté for 7-9 minutes until onions are translucent and tender.
Arrange the chicken in one layer over the onions. Nestle the cranberries around the chicken. Lay the lemon slices over the top. Pour the chicken stock over the chicken and cranberries. Bake for 30 minutes in the oven or until chicken juices run clear. Don't be worried to leave it for another 20 minutes if needed.
Serve over white rice. The juices are absolutely lovely with the rice.