Participation in an FSA and HSA

Can an employee participating in a Cafeteria Plan FSA also establish and use a HSA?

Only if the FSA is designed not to cover impermissible medical expenses: a "special purpose" FSA.  For example, the FSA could cover dental expenses.

This response assumes that the employee is otherwise eligible to have an HSA

To clarify, an employee cannot contribute (or have contributions made on the employee's behalf) to an HSA if he or she participates in a general purpose FSA.  If an employee has an existing HSA, he or she can "use" both the HSA or a health FSA to reimburse eligible medical expenses.