If you don't have these veg add what you do. I like broad beans and a handful of kale.
Start by making a sofritto by gently sautéing finely chopped onion, carrot and celery. Add crushed garlic, chicken stock, black pepper and beans and cook for 30-45 mins. Once everything is soft add leftover roast chicken, parsley and a splash of white wine vinegar. Check for seasoning and serve.
Here is my guide.