I haven't had this at Mon Ami Gabi, but making any type of compound butter is fairly straightforward. The basic idea is to mix raw butter with other ingredients and then rechill (though this is optional). If it is a merlot reduction, I presume they reduce merlot to a desired consistency, add salt and maybe pepper or herbs (if desired), let it cool, and then mix with butter. The two variables are how long to reduce the merlot and what is the desired ratio of merlot to butter.
You can also make this using pan drippings. For example, you roast some meat. After it is done, remove it from the pan. Add the merlot to the pan, heat, and scrape up the browned bits from the bottom. Reduce the merlot. Then add butter, salt, pepper and herbs. Then strain. This will be more of a sauce than a hard compound butter.
James Peterson, in Sauces, gives a recipe for the classic French "Marchand de Vin Butter" (Wine merchant butter): Basically, reduce a cup of wine with a minced shallot and 5 cracked peppercorns. He then adds salt and meat glace, and reduces until you get a few tablespoons of syrup. Mix this with 5 oz of butter, chopped parsely, and 2 teaspoons of lemon juice. I'm sure you can find other versions on the web.
Last edited by
Darren72 on April 21st, 2009, 3:50 pm, edited 2 times in total.