A bouquet garni consists of 4 to 5 sprigs of parsley, 1 bay leaf, and 2 to 3 sprigs of fresh thyme (or ¼ teaspoon dried leaves), which I tie up in a celery rib cut in half.
The reason for tying the ingredients together is to enable you to discard them easily once the cooking is finished. If you plan to strain the stock or sauce in which the bouquet garni has been cooking, it is not necessary for you to tie up the ingredients, although it makes skimming easier.
Place the fresh or dried thyme in the hollow of the celery rib half and cover with the bay leaf and parsley sprigs
Cover with the remaining celery rib half and tie together.
Double Bouquet Garni: If a recipe calls for a double bouquet garni, just double the herbs and tie with the same celery rib.