Soft fruit, such as berries, melon, and papaya, can be puréed as is. Firm-fleshed fruits or those that discolor (pears, for instance) should be poached in a simple syrup made from sugar and water in equal amounts by weight. Poaching before puréeing softens the flesh and preserves the color of the fruit. Most vegetables need slow, moist cooking (such as braising) before they'll yield a purée with deep, satisfying flavor. Almost any vegetable, including tomatoes, red peppers, leeks, and carrots, will lend itself to making a coulis. Starchy vegetables, however, don't have the natural juices needed for a flavorful sauce.

Given its supporting role, coulis is most often simply seasoned. While herbs and liqueurs make nice additions to a coulis, often all that's called for is salt and pepper for savory sauces, sugar and a touch of lemon juice for sweet coulis.

To make a coulis, purée the prepared fruits or vegetables using a food processor, blender, or food mill. If the purée needs sweetening, stir in some simple sugar syrup, which will dissolve more easily than straight granulated sugar. Alternatively, use either superfine or confectioners' sugar--or even honey--as a sweetener.

To remove seeds, use a fine conical strainer, also known as a chinois mousseline. In addition to having an exceptionally fine mesh, the chinois mousseline is efficient because its shape allows the pulp to collect in the pointed bottom of the sieve. When the pulp has settled, you can easily press out the last bit of juice with a small ladle.