Caching key in LINQ EF framework
===

I would like to implement caching in an application that I inherited. The DAL uses LINQ to SQL. Generally, I would use type/id as a key for the cache. However, the DAL Get method takes a lambda where clause as following:

    public static IEnumerable<TEntity> Get(Expression<Func<TEntity, bool>> whereClauseLambda)
I am trying to find a good way to generate a cache key, so I can do a look up in the local cache before going to the database, but can't think of  a good/straight forward way.
What are some potential options I could be overllooking? Thanks!