Thickening with flour I've been making braises and I'm intrigued by the different methods for thickening the sauce with flour. I've come across five strategies:


Coating browned meat with flour and cooking the flour before adding browned vegetables and liquids.
Coating the meat with flour before browning.
Coating the vegetables with flour after browning and cooking the flour before adding the browned meat and liquids.
For certain braises, Escoffier recommends mixing in roux before adding the liquids.
Whisking in beurre manié before reducing the sauce. (I suppose that the flour cooks as the sauce reduces.) Some recipes use a slurry with cornstarch or other starch instead.


What are the relative merits of each approach? Are they interchangeable?
Unless you are making a vegetarian braisé, I would suggest not browning the vegetables.

If you brown the vegetables and add them too early in the pot, then they will cook too much and be mushy in the end product.

I prefer not using flour when browning the meat too early because I tend to burn it; so I brown the meat, and after that, do a roux and re-add the meat and add liquid.

As for using beurre manié, for me it is just a thickening agent and is done at the end and should not really add additional flavour to the dish.