I have a pos coffee shop setup and I want to configure a sandwich with bread, beans and eggs.

The sandwich would be make to order and only sellable, not purchaseable, correct?

But what about the bread, beans and eggs? 

Bread would be bought by units and only sold as part of a sandwich. 

Beans would be bought per pound, assume no processing and sold only as part of a sandwich. 

Eggs would be bought by units but sold both as part of sandwich or as a side or extra topping.

And do I have to install manufacturing to define the make to order route of the sandwich as: 

1 bread 

1/2 pounds of beans 

1 egg 

?