Add a method to the OracleFunctions class to allow me to inject my old SQL snippets into the executed query. i.e.

var result = from x in ents.MyTable
where x.MyThing > 10
&& OracleFunctions.CustomSQL("MyFunction(:MyID, :MyThing) > 1", new OracleParameter("MyID", x.ID), new OracleParameter("MyThing", x.MyThing))
select x;

would result in something like the following

SELECT
"Extent1".ID, "Extent1".MyThing
FROM
MyTable "Extent1"
WHERE
"Extent1".MyThing > 10
AND MyFunction(:MyID, :MyThing) > 1