Sorry, not many good choices. You could try a typical five-star hotel breakfast buffet, which are not much different from elsewhere in the world. The best, in my opinion, are the W and the Grand Hyatt. Both have all of the typical international dishes as well as a handful of local choices. The Hyatt has a Turkish theme and is pretty good. The W is more elegant, including falafel among the local items.

The only place I can even think of that has breakfast other than a hotel is Ric's Kountry Kitchen, which styles itself as sort of a Tex-Mex diner. Or there are some Arabic restaurants, like Al Shami Home Restaurant or at least a couple of the places at Souq Waqif, that are open 24 hours and have non-breakfast items. This is a real lament of mine in Doha -- there is really no breakfast culture. I would be happy even with an International House of Pancakes, and I rejoiced when McDonald's started serving breakfast recently.

If you're there on Friday mid-day, or Saturday in case of a couple of places (maybe the Marriott), you can visit a lavish buffet brunch at any five-star hotel, though they tend to start later, so check the internet depending on what time your flight leaves.