I have a question regarding fast food during coronavirus outbreak, does eating from fast food restaurants make people sick if someone cook the food and he/she was coronavirus positive?

Yes, if...: According to most common regulations in restaurants, any symptomatic (of any infectious disease) worker must be stopped from direct contact with food. However, COVID-19, as many other viruses, can stay suspended in air as little droplets, and live on surfaces. So, virtually the possibility exists but now there is no scientific information about that specific way; airway is the most susceptible.