Heat a large soup pot over medium heat and add olive oil and butter. Once melted, add diced onion, carrots, and celery. Sauté for about 5 minutes until softened.

Stir in turkey or chicken stock, cooked turkey, bay leaves, salt, and pepper. Increase heat to a gentle boil.

Add giant couscous to the pot. Reduce heat to medium-low and simmer for about 10 minutes, stirring occasionally, until couscous is tender.

Remove from heat, discard bay leaves, and stir in chopped parsley. Adjust seasoning and serve hot.