4 cups good-quality low-sodium turkey or chicken stock
1 Tbsp soy sauce
6 Tbsp flour
Salt and pepper
Melt 1 tbsp butter in large saucepan over medium heat. Add onion, garlic, carrot, celery, neck, and giblets; cook until browned.
Add stock and soy sauce; bring to a boil, reduce heat and simmer for 1 hour, then strain. In large pan over medium-low heat, melt 2 Tbsp butter; add flour, whisking frequently, until it turns deep brown.
Slowly whisk in the stock, bring to a boil, then reduce heat and cook until thick. Salt and pepper to taste.