She is currently writing a historical book about food, which will include old recipes and the history behind them
A. At the moment, she is collecting recipes and the historical information behind them for the book which she intends to write on food
B. The book she is writing at the moment is on the history of food, with old
recipes and stories behind them
C. There are many interesting historical facts behind the old recipes to be found in her book, which is a history of food
D. The book she is writing is actually a historical book, but it also contain information about old recipes
and the stories behind them