Steak Frites with Bearnaise Sauce

One of the best sauces for steak, Bearnaise sauce is a classic based on Hollandaise sauce. I tried a couple of new things in this recipe, not entirely successfully! But will definitely try it again.
Ingredients needed:
2 egg yolks
125g butter
fresh tarragon
fresh or dried chervil
200 ml white wine
100 ml white wine vinegar
salt and pepper
Good quality steak, Tenderloin / Filet or New York Strip / Sirloin
Fries
I tried out the method of saving my Bearnaise sauce in a vacuum flask until use so I'm not rushed at the end. Great idea, but remember to shake up the sauce before pouring! ;)
This is the Thermos I used: amzn.to/3PV8MzM. I bought this one only because it stated that it would keep liquids warm for 24 hours. We will see about that :)