Complex sentence: The recipes rarely give any details of the heat or time required for cooking: thus the pancake recipe merely says "make them brown"; but the book takes care to explain how to roast meat so it is properly cooked.
Split into simpler sentences: The recipes rarely give any details of the heat or time required for cooking: thus the pancake recipe merely says "make them brown". But the book does explain how to roast meat so it is properly cooked.