Robert Rothschild Farm Blue Cheese Dijon Mustard. Gluten free. Gourmet mustard. 1-800-356-8933/robertrothschild.com. Blue cheese, honey and spices are combined to create a savory and sweet mustard. Our blue cheese dijon mustard makes an ordinary burger extraordinary with the unique tang of blue cheese. Use as an accompaniment to a cheese platter, create a wonderful vinaigrette or add a burst of flavor to a picnic sandwich.