Should you add it right after heating the fat? Or after youre done sauteing all the veggies so they soak all the wine? Or should you start with the wine THEN add the fat?
In sauce making, you would add liquid (wine, water, broth, etc.) to release the fond (browned bits) that adhere to the bottom of your pan. Therefore, as related to your question, after sauteing. The purpose is not to soak into anything, but to incorporate the flavor from the fond and the liquid into your sauce.
usually, it would be after you cook down the aromatic vegetables in the left over bits in the pan.
For example, after pan-frying a steak:
- pan-fry the steak.
- remove excess fat.
- add in shallots (and other veggies), let it cook down.
- add wine, reduce.
- add stock or demi-glace and let it reduce
- add cold butter and emulsify.