A method of preparing a frozen vegetable piece, preferably a potato piece such as French fries, wherein the inner part of the vegetable piece has a temperature above 0 ° C while the outer layer of the vegetable piece is below 0 ° C. Slow the vegetable pieces until the vegetable pieces are completely frozen by contacting the vegetable pieces for a short period of time with an inert substance having a sufficiently low temperature for a short time and contacting the vegetable pieces with air Freezing. [Selection figure] None冷凍野菜片、好ましくはフレンチフライなどのジャガイモ片を調製する方法であって、野菜片の内側部分が0℃超の温度を有しつつ、野菜片の外層を0℃未満の温度にするのに十分な長さの時間、十分に低い温度を有する不活性物質に野菜片を短時間接触させるステップと、野菜片を空気に接触させることによって、野菜片が完全に冷凍されるまで野菜片を緩慢に凍結するステップとを含む、方法。【選択図】なし