Hello
You find cooked harees in 2 places.

1. In a steet named Mogwalina (Behind M.P. Traders), there is a masjid known as Sudani Masjid, which a Thai Resturant named Thai Smile, just beside it a arabic restaurant with lots of Qatari's generally waiting in Land Cruisers. You will often see the waiters dressed in Blue. You can get harees from there. 1 tray cost about 15 QRS and its yummy tasty.

2. Second is the place as mentioned near Ramez (Airport Road) near this superbike repair shop (i Think Dream Team) there is a shop named HAREES, written in arabic. You get nice Harees from there as well.

If i have any info, i shall let you know.

Generally during Ramadan most of the Qatari people staying in Big Villas offer Harees to people for free along with Majbus Leham (Mutton Biryani) if you have a friend working there they can deliver it at your house.

Good Luck