How to make a roux

What is a roux?

A roux (pronounced 'roo') is the name given to the cooked mixture of butter and plain flour that thickens and forms the base of various sauces, particularly the white sauce (béchamel). It's also an essential ingredient in classic recipes like a classic lasagne, fish pie, moussaka, macaroni cheese and cauliflower cheese.

It consists of equal quantities of butter and plain flour. The fat is melted, the flour is mixed through over a gentle heat. Hot liquid is then gradually mixed into the paste to make a silky sauce which needs a few minutes more cooking before using.

What are the right ratios for a roux?

I always use an easy-to-remember equal quantity of flour to butter. This gives a good all-round thick paste and makes it easier to incorporate the liquid. Your mixture will be less likely to go lumpy.

A good ratio for a basic white sauce is:

• 50g butter
• 50g plain flour
• 500ml whole milk

source https://www.bbcgoodfood.com/recipes/how-to-make-a-roux