Peter Gordon: How potatoes stack up best
I want to make little potato gratin stacks to serve with eye fillet. Can I buy containers that will hold them in shape in the oven? - Rebecca Lawson
You can make one large gratin and cut out stacks with a cookie cutter, which may be a little wasteful, but is the easiest option(snack on the leftovers while you cook). Otherwise buy metal, ideally stainless steel, cookie cutters and fill these with the gratin mix, lining the base with baking parchment and foil to stop it leaking out. Or you could go rustic and head to a plumber's yard for unpainted pipe offcuts.
Where can we find truffles in New Zealand? Or do we have to source them from overseas through online shopping? - Christabel
Depending where you live you should contact your best deli/foodstore. Also look up this website as a start, as I know they'd be keen to help you find them.
When I read a restaurant menu I've never understood the difference between a hollandaise sauce and a beurre blanc sauce. What is the difference? Can you substitute one for another? - Tracy Matson
Hollandaise contains eggs, beurre blanc doesn't. The former is whipped over a pan of simmering water with melted butter whisked in. The latter is a reduction of vinegar (basically) with unmelted butter whisked in. They can be interchanged, but beurre blanc on poached eggs would be too rich for brunch.