Typically you order the dish and it comes with the sauce "baked in". The only time that you physically add salsa yourself is when you are eating tacos or a few

Typically you order the dish and it comes with the sauce "baked in". The only time that you physically add salsa yourself is when you are eating tacos or a few other dishes, and even then, all of that is going to be prepared fresh, in-house. Even at home you prepare it yourself. The idea of buying a distinct sauce at a store to keep on your counter or in the fridge is kind of foreign.