Flour substitute in roux?
I would like to try and make a blonde roux so that I could make a veloute sauce... however my girlfriend is allergic to wheat so I can't use flour as the ingredient. I was wondering if it's possible to subsitute the flour with 1/2 the amount of cornstarch instead? If so, how does this effect the taste of the roux and the veloute sauce? Thanks so much in advance!