Stracciatella soup is very Roman, and nothing similar in British cuisine, so worth thinking about.
Rome has its own cuisine, with different meals on set days of the week, that tied in with the daily markets. So it might be fun to find out about that, and on one day make the Roman meal for that day.
A seafood linguini would be nice, depending on what is available locally. A stew, perhaps of sausages, served with polenta. If you plan to have something like lamb chops or roasted fillet of pork, perhaps do something interesting with the vegetables, maybe courgette in breadcrumbs.
Another idea might be to look at food from Sicily, and have a Sicilian night? Perhaps you could find some Italian cheeses for lunches, Gorgonzola etc.
Rome is my all time absolutely favourite city, what a pity your trip is cancelled. I hope you get there one day!