We make a lot of spinach madeline where I work and I am having some problems getting it to thicken. I add a flour and water paste to the chopped spinach and cheese mixture but when doing large batches it does not want to thicken. Should I add more of the flour and water paste (which I personally don't like using), do I need to cook it longer and/or cook it at a higher temperature? I afraid too much paste will take away from the taste. Any suggestions would be greatly appreciated!