As we are living in an Islamic State, so any fast food outlet serving any food is definetly HALAL. Except for 5 star hotels where they are quiet liberal in serving foods as an exceptional only. Still, before intaking any meal it is our obligation to make sure that we are consuming food or liquid is according to our religion. look for words like Pork,Ham in the menu and avoid such restaurants or dish.
Overall, as i was born in 1980 and since then living here, i think HALAL products are easily & openly available in Qatar