A compound butter, that is a butter that you have mixed with flavoring components, is a great addition to any kitchen. We often use them at the restaurant to make a final addition of flavor to foods that don't otherwise have a sauce, such as grilled meats. Here's a walk-through of the Cabernet butter that I made for our filets mignons last night. Use the same method and vary the ingredients for any other flavor of butter that you'd like to make.
Cabernet Compound Butter
Here you see the ingredients that you'll need: 8 fluid ounces (1 cup) of red wine, 1 tablespoon each of minced thyme and freshly cracked black pepper, 1 pound of sweet butter at room temperature, 3 large shallots in fine dice, and a teaspoon of salt.
Put the red wine, shallots, and thyme in a non-reactive pan over high flame and start the wine reducing.
While the wine is reducing, cream the butter, salt, and pepper either by hand or in a mixer.
This is what you're aiming for: all the wine save two or three tablespoons is evaporated. Cool the wine reduction to room temperature—or else!
Add the cooled wine reduction to the butter and mix thoroughly. Lay a sheet of kitchen film on your work surface, place half of the butter on the film, and roll into a log. Repeat with the other half of the butter.
We store our butter in the freezer to keep it very firm. To serve, we slice a round off the log right through the film, then we peel the film off the round. These butters keep for a long time in the freezer so you can make a variety well in advance and have them on hand at any time.
Try this with rosemary, garlic, and lemon zest for lamb; dill, chervil, and lemon zest for fish; roasted garlic and black pepper for ribeye steak; rum, pineapple juice, and toasted coconut for shrimp; chipotle adobo, cilantro, and cumin for skirt steak; espresso and ancho chile for elk; lobster stock, cognac, and chives for scallops; garlic, sour orange juice, and oregano for pork, etc. You get the idea. The combinations are endless.