In my last few weeks in Brazil, I heard the term à francesa used twice, in two different ways. In one instance, I ordered a pizza from a joint near my house and they asked me if I wanted it the French way. Hoping that didn’t mean they were going to put snails on it, but open to something new, I said, “sure, go ahead”.
When it came and I opened the pizza box, there was nothing special about the pizza. Apparently they forgot the French part but, no worries, I looked it up anyways and saw that it means to cut it in squares, not slices. I then became tempted to think of what other food items I could have asked for ‘à francesa’ just to see if I could have gotten away with it. If, for some reason, you forget the new term, you can always just say em quadrinhos (in little squares) or even pizza aperitivo (the formal name, I believe).
The second instance of the term was when someone at a get-together told me later on that I had left the party the French way. I thought to myself, but there was no kissing on the cheeks (and certainly no tongue involved), since all I did was to just sneak out. Surprisingly or not, the French happen to say filer à l’anglaise, or flee English-style. In any event, as you may know, one potential downside (depending on how you look at it) to parties with Brazilians is that leaving takes a long time. Sometimes I’m so lazy to do so that I just stay until the party dissipates, but many times I use the sair à francesa trick.
And as a bonus, if you ever wondered about the phrase “Pardon my French”, it is said to come from a time when the English used many French words in their speech and thus would apologize if they were in fact using a word that was not understood by the other party. Despite the rise of anglicisms in Brazil, I’m definitely not waiting for the day when Brazilians say “pardon my Portuguese”…

Haha, didn’t hear this expression… yet. I only heard “a francesa” for the nails which is quite common. But the second way you described is quite interesting :
This page http://fr.wiktionary.org/wiki/filer_%C3%A0_l%E2%80%99anglaise#Traductions show that this kind of behavior is English or French depending on the country.
In English, Spanish, German and Portuguese it’s “à la française”.
In French, Croat, Italian and Polish, it’s “à l’anglaise”.
For now, it’s a draw.
By the way, snails on pizza are excellent! I have a good address near Montmartre ;)
I’ve never heard that! Going to ask for it next time we order pizza and see what happens.