Wow, so that is what you call a bouquet garni?! Now I am just a culinary student and a chef so maybe I am just lost. However, what Ed Buchanan has descibed here is not a bouquet garni at all; what he has described is a sachet d'e'pices. A sachet d'epices is made by tying seasonings together in cheesecloth. A standard sachet consists of peppercorns, bay leaves, parsley stems, thyme, cloves and optionally, garlic. The exact quantity of these ingredients is determined by the amount of liquid the sachet is meant to flavor.
Now what a bouquet garni is; is a selection of herbs (usually fresh) and vegetables tied into a bundle with twine. A standard bouquet garni consists of parsley stems, celery, thyme, leeks and carrots.
As for his "studded onion" or what it is called a oignon pique' (also known as an onion piquet). This is a similar technique as to the garni and sachet, however it is less commonly used. In this technique, you prepare the onion by peeling it, trim off the root end and attach one or two bay leaves to the oignon pique' using whole cloves as pins.
The oignon pique' is then simmered in milk or stock to extract flavors.
I'll also give you one more you may never had heard of, an oignon brule' French for "brunt onion," is used to flavor and color stocks, sauces and soups such as consomme'. To prepare an oignon brule', peel the onion, trim off the root end and cut in half. Place the onion halves cut side down in a dry skillet over medium-high heat. Cook until the onion halves char and darken (caramelize). The oignon brule' is then simmered in stocks or soups to give them a clear Carmel color.
Now, I knew most of this but just in case I gave you the definitions as I pulled out of "ON COOKING, FOURTH EDITION," page 188. Feel free to look it up if you don't believe me. Thank-You.