Hello - please let me know if I am missing something.  
Many times I will see subforms for many-many relationship based on a query, but it would seem that one can create a functioning form with subform for tables with a many-many relationship.  

For a test I made a simple table with 2 fields (PersonID, FirstName) and 4 records, a second table PizzaToppings (ToppingID, Toppings) and a JunctionTable (PersonalToppings) with 3 fields (JunctionID, PersonID, ToppingID...I didn't use a composite key, just let Access use autonumbers).  

The main form is a single form based on the Person table.  The subform is based on the junction table with a combo box that gets the ToppingID and the Topping (ToppingID column width is set to zero).  This seems to work, I can modify or add records bit I wonder if I am missing something basic.  By sidestepping the use of a query is there a risk of some error that eludes me?  Thank you