There are already plenty of robots capable of performing household chores. A few companies are working on robotic machines to cook our meals in the future. You can always build your own sandwich making robot though. Take Sandwich-o-matic for instance. It is an automated sandwich making machine built with servos and a motor to pull the toaster sideways. The parts are controlled using a Photon and an Arduino.
As you can see in this video, Sandwich-o-matic is not perfect, but it can make a sandwich with the right ingredients loaded. In the future, it will have more topping options and condiments.