Parmo is breaded chicken, covered with bechamel sauce and topped with cheese.
The Hairy Bikers do a slightly healthier version.
Wiki has this to say about its origins:
Parmo is said to have been created by Nicos Harris, a chef with the United States Army in World War II. He was wounded in France, but was brought to the United Kingdom to be treated in a British hospital. Eventually, he moved to Middlesbrough and opened a restaurant, The American Grill, on Linthorpe Road, where he created parmo in 1958. His son-in-law, Caramello, still lived in Teesside as of 2014, continuing the family tradition.