Popular on pasta or chicken, walnut sauce is a type of sauce made primarily from toasted walnuts. Often made with dry white wine, walnut sauce is created by toasting and grinding walnuts before adding spices and liquid elements. Walnut sauce is normally considered a reduction, which means the ingredients are simmered down to approximately half their original volume. In addition to chicken and pasta, this sauce is also sometimes used in vegetable soups and as a creative topping for asparagus.
Besides walnuts and white wine, garlic, parsley or basil, and Parmesan cheese are usually added. Heavy cream, whipping cream, or milk is almost always included in walnut sauce, as is butter. Shallots, red pepper, or onions may be included as well. At least one spice, such as cinnamon, rosemary, or nutmeg, is generally found in most sauces.
Although dry white wine is usually used as the liquid base for this sauce, white wine vinegar or extra virgin olive oil is sometimes used instead. If the sauce will compliment chicken, chicken broth can be added for extra flavoring. When white wine is used, the alcohol is burned off during the reduction process, so the finished sauce is not alcoholic. The white wine flavor, however, remains.
To prepare walnut sauce, the nuts are toasted or sauteed in a small amount of butter. Toasting nuts is a relatively quick process, only taking a few minutes. Cooks can determine when nuts are sufficiently toasted both by their golden color and their fragrant aroma. Toasting nuts can be tricky, however, since they can easily burn if not carefully watched.
The nuts can be chopped before or after toasting. Chopping can be accomplished by hand or in a food processor. If chopping after toasting, spices can be evenly and thoroughly mixed by including them in the food processor with the nuts. Occasionally, a recipe suggests placing all the ingredients in the food processor to blend to a paste before cooking. Most recipes, however, do not suggest this.
Once the walnuts are toasted, the garlic is often added and sauteed. If shallots, onions, or peppers are included, they are usually added as well, often with the spices. The wine and milk or cream are usually added last, and the sauce is then allowed to simmer and reduce. Some recipes call for spices to be added after the sauce is reduced. These recipes usually allow the sauce to simmer again once the spices are included.