Families are really busy these days and often times people don't have enough time to purchase, prepare, cook and clean for each meal. If you are cooking for one, often times it's not cost effective because of spoiling food. If you have a large family, purchasing in bulk saves on costs. The option to eat out is often limited to great tasting but bad for you options. Restaurants put these options because they sell. High in salt, fat and sugar. There are fewer health options that could taste good and also be good for you like home cooked food.
A restaurant that has multiple chefs that specialize in a type of cuisine. Where a person could go online and select options for food for the day/week/month or year and their orders would be routed to a sponsored local restaurant where the food would be shipped and prepared the day that you intend on visiting. The more you schedule orders the cheaper it would be per plate. So a single person could take advantage of bulk purchases like larger families do by placing a weeks worth of orders.
There isn't a service like this so there is a first mover advatange. Some potential competitors are Uber Eats (https://www.ubereats.com/) which deliver food from restaurants. Blue Apron (https://www.blueapron.com/) is a service that delivers food to your house but you are left to prepare, cook and clean.
A metric that could be used could be piloting this concept in a metropolian area and establishing a physical pressence. A variety of Chefs could be higher based on their expertise and order could be taken to confirm the model. Scaling the concept would prove to be challenging but could be done with the proper execution.