Yatais and/or food stalls

getting ready to visit in 3 weeks for 35 days, when i visited 7 years ago i remember there being a lot of food stalls set up at Sensoji Temple and some parks. when i went 2 years ago i couldn't find any anywhere. Is there a part of Tokyo or certain time i can go somewhere to find Yatais and/or food stalls set up? Taking two friends this time and i think the street food would be a great experience.