It has a rich roasted characteristic of butter and roux that is characteristic of butter, and when applied to frozen foods, it has good cooking characteristics in a microwave oven (for example, there is no uneven heating and easy re-gelatinization) Provided is a method for producing roux for preparing a cream sauce that combines a fast return) and a good texture after thawing and heating (eg, having a smooth texture). (A) stirring butter to obtain creamy butter; (B) mixing creamy butter obtained in step (A) with active gluten to obtain a raw material for roux; C) The raw material of roux obtained in step (B) and modified starch are mixed to obtain a mixture, and (D) the mixture obtained in step (C) is heated at a temperature equal to or higher than the gelatinization temperature of modified starch. A method for producing roux, comprising the step of heating to obtain roux.バターに特有のコク、及びルウに独特の焙焼感を有し、しかも、冷凍食品に適用した場合において、電子レンジでの良好な調理性(例えば、加熱ムラがなく、再糊化が容易で戻りが速いこと)、及び、解凍及び加熱後の良好な食感(例えば、滑らかな食感を有すること)を兼ね備えているクリームソースを調製するためのルウの製造方法を提供する。 (A)バターを撹拌して、クリーム状のバターを得る工程と、(B)工程(A)で得たクリーム状のバターと、活性グルテンを混合して、ルウの原料を得る工程と、(C)工程(B)で得たルウの原料と、加工デンプンを混合して、混合物を得る工程と、(D)工程(C)で得た混合物を、加工デンプンの糊化温度以上の温度で加熱して、ルウを得る工程、を含む、ルウの製造方法。