Aside from the a "a la O'reilly", I used the spices and herbs because I want my exercises to be like recipes.
I didn't want to put together training like "this is 100 different vulnerable pages, now go nuts on them!!". It's just not how I see things.
I want people to learn penetration testing like they can learn how to cook:
You use technics together and follow instructions to get something amazing.
Then you can apply the new technics you learnt for other dishes...