Tell you what, Edfilho. If you're ever in my neighborhood, I'll treat you to something from Taco Bell, your choice. It's the least I can do for an Atleticano.
As to the mustard, not having it must just be a Minas thing (Uai!). They do things quite a bit differently there than they do in other parts of Brazil.
@ LeHah
As far as big fast food places: most of the cities I lived/worked in didn't really have any chain restaurants. When I lived in Belo Horizonte, they had things that you find in the U.S.A. like Pizza Hut and McDonalds, as well as some nice Italian places and lots of good traditional Brazilian places, but in most of the other smaller cities in Minas Gerais it was more like a bunch of corner hamburger stands (which were really quite good, in my opinion) or the ever-famous Brazilian Barbecque churrascarias. Man were those good.
Also, a lot of the time bread stores would serve as fast food for me. They had some pretty nice stuff in there, too, my favorite being "sonhos" which are a sort of baked good somewhat similar to a donut. They had all sorts of breads, some with meat and cheese, some in a sort of pizza mixture, and so forth. It was best when they would fill sonhos with doce de leite (the best English translation I can find for that is caramel, but it really doesn't capture what doce de leite is, and I have never found anything in the U.S.A. that tastes quite like it, though I think they call it dulce de leche here.)
Keep in mind, though, that I spent most of my time in smaller cities and towns like Teofilo Otoni, Sabara, Governador Valadares, Nanuque, and other places you have probably never heard of (people in Minas are kind of considered to be hicks), so this shouldn't be taken as representative of Brazilian fast food as a whole. I'm sure Delance, Eder, Edfilho, and the others can fill you in on what they have in their areas, which is probably much more comprehensive than what I had in my smaller towns.