Preheat grill. Using side burner or top of grill. Heat olive oil in a medium saucepan. Add 1/2 leeks and fennel and cook until soft. Add the thyme and barley and cook for 1 minute. Place the broth and saffron in a large saucepan and bring to a simmer. Begin by adding 2 cups of the stock and stir until the barley has absorbed the stock. Add the remaining leeks and fennel and 4 cups of the broth. Cook until barley is tender and the mixture is creamy, stirring often, about 30 minutes, during the last 10 minutes add the asparagus. If the mixture appears dry, add the remaining 1 cup of stock. Add the lima beans and spinach and cook for 2 minutes. Remove from heat and add cheese, salt and pepper to taste.