Rouille is a thick sauce that is often used as a garnish with fish or fish-based soups. The actual name for the sauce is actually the French word for rust. This is because of the reddish brown color of the sauce when it is prepared with a traditional recipe.
There are actually two different ways to create rouille. The traditional method of preparing this red sauce is to use a combination of olive oil, chili peppers, and cloves of garlic. Breadcrumbs are added to give it the proper texture. Along with these basic ingredients, the oil-based rouille may also include a wide range of spices, depending on the preferences of the chef. Saffron, orange peel and basil are examples of spices that often find their way into it.
A second approach to rouille makes use of mayonnaise instead of olive oil. Either chili peppers or small pieces of red pimentos are added to provide some of the rust color to the sauce. Garlic is also often used in the preparation of this variety. Because the mayonnaise has a thicker texture, the use of breadcrumbs is not necessary. Like the olive oil-based rouille, the mayonnaise-based version accommodates a wide range of spices.
One of the more common presentations for rouille is as a garnish served along with bouillabaisse, a fish soup hailing from France. The soup contains various types of fish along with many different types of spices. Many of the same spices can be used effectively in rouille as well, allowing the garnish to compliment the taste of the soup.
Along with soups, rouille also is a fine accompaniment to baked or broiled fish. Since it is often made with chili or other hot peppers, the sauce is also a favorite with fried fish in some sections of the American South. It is just thick enough to apply a small amount to each bite of the fish, and adds another layer of flavor without masking the taste of the fish.
Making rouille at home is not difficult at all. Since the sauce requires relatively few ingredients, it is possible to prepare a batch in a very short period of time. However, preparing it at least a few hours in advance allows time for the ingredients to intermingle in the sauce, enhancing the flavor of the finished product.
For people who do prefer to purchase rouille already prepared, there are commercial versions of the sauce. Packaged sauce is often sold in high-end supermarkets as well as kitchen boutiques and food specialty shops.