A zesty horseradish cream sauce with caramelized roasted garlic and fresh thyme. Perfect for serving alongside Prime Rib, spread onto steak sandwiches, dolloped onto baked potatoes, or as a dip for shrimp.
Cut the top off of the garlic head, exposing the cloves. Remove any loose papery skins.
Place garlic head on a square piece of foil large enough to wrap around it fully, or in a small cast iron cocotte. Drizzle garlic with olive oil and season with a pinch of kosher salt.
Wrap the foil around the garlic to seal, or place the lid on the cocotte. Bake for 40-60 minutes, until golden and caramelized.
When cool enough to handle, squeeze garlic cloves from their skins and chop finely.
Make the Sauce
In a medium bowl, stir together sour cream, horseradish, Worcestershire sauce, and chopped garlic cloves. Mash some of the chopped garlic with the back of the spoon as you're mixing.
Stir in thyme, salt, and pepper. Cover and refrigerate for 3-4 hours for the flavors to develop. Season to taste with additional salt and pepper before serving.
Buying Prepared Horseradish:
For this sauce, I use refrigerated, jarred "prepared" (or "pure") horseradish. Read the label before buying on this one; it should be simply packed with salt and vinegar. Shelf-stable varieties contain other ingredients and flavoring agents, and will not produce the same results in this sauce.Heat levels can vary significantly by brand, so adjust the quantity as needed for the horseradish you've purchased.The flavor of the horseradish will not be at its most prominent when the sauce is first mixed, but will develop as it rests. If you prefer a milder sauce where the roasted garlic is the more prominent flavor, reduce the prepared horseradish to 2 tablespoons.
For easy entertaining, you can roast the garlic up to 5 days in advance and store, wrapped, in the refrigerator.