Preheat the oven to 300 degrees Fahrenheit. Grease a baking dish, and set aside.
Spread the bread cubes on a baking sheet, and bake for about 15-20 minutes until they are dry and lightly toasted. Remove from the oven, and set aside.
In a large skillet over medium heat, add the olive oil and butter. Once the butter has melted, add the chopped celery, carrots, red onions, thyme leaves, and minced garlic. Sauté for approximately 10 minutes or until the vegetables are tender.
Stir in the olives, parsley, salt, black pepper, and dried cranberries (if using).
In a large mixing bowl, combine the toasted bread cubes with the cooked vegetable mixture. Gradually pour in the chicken broth, stirring gently to combine and moisten the bread evenly. Adjust the amount of broth as needed to achieve the desired stuffing consistency.
Transfer the stuffing mixture to the prepared baking dish.
Bake in the preheated oven at 350 degrees for 20-25 minutes until set and golden brown.
