The first thing to do is to find out how many people would be interested. Stop 200 people on the street, ask them let them taste the food.
Go to another location, stop another 200 people, ask them and let them taste the food.
Go to a 3rd location, stop 200 people, ask them....
Only when you have conducted market research on at least 1,000 people chosen from various sites within the city will you have an idea whether it is worth starting a business.