I have an object model that looks like this (pseudo code):
class Product { public ISet Recommendations {get; set;} public ISet
Force an eager load on the part of the graph you care about using the NHibernateUtil class.
NHibernateUtil.Initialize(Product.Recommendations);
See the link below for further details.
http://nhforge.org/wikis/howtonh/lazy-loading-eager-loading.aspx