The oil obtained from pressing hazelnuts. The brown colored oil has a slightly sweet, nutty taste and is generally used as a flavoring for baked goods and for some sauces. It is excellent when brushed on fish and it works well as a marinade. It can also be added to mildly flavored oils and used as a base for salad dressings. Hazelnut oil is expensive and it is usually found in gourmet shops, although some supermarkets may have a supply. It is very popular in French cooking.