A small knife with a short, inward-curving blade, designed to produce seven-sided, football-shaped vegetable portions (the tournée cut, the source of its name) in a single arcing motion. The hook-like profile, which gives the knife its common nickname of "bird's beak," lets the The cutting edge that curves outward away from the spine; here it curves up toward the tip rather than down sweep around the contour of a potato or carrot while the cook turns the vegetable against it. The same curve makes it handy for in-hand carving of round fruits and vegetables, such as peeling an apple or hulling a strawberry. It is nearly obsolete in modern home cooking but remains essential in classical French culinary training, where the tournée cut is a rite of passage.
Primary tasks: the tournée cut, plus similar curved-blade, in-hand work on round produce.
Ideal steel: any easy-care stainless does the job, since the cuts are short and low-stress. A simple, corrosion-resistant alloy like X50CrMoV15 or 14C28N takes a fine enough edge for the job and shrugs off the acidity of fruit. For a knife this single-purpose, edge geometry matters far more than exotic metallurgy; see the construction notes on grind and bevel.
Limitations: this is a single-purpose tool. A standard paring knife handles 99% of the cases where a tournée knife would also work, and most cooks reach for one out of habit. Keeping the curved edge sharp also takes a little patience, since it does not lie flat against a stone; the care section covers how to maintain a curved profile.