Piazzale Michelangelo

Most churches will not let you bring food or drink inside. If you have it all hidden in a bag, it may be okay, but it depends on how obvious it is that it's food? I would guess it's like the knees rulesometimes they enforce that your skirts/shorts must be below your knees, other times they don't. But maybe other people have more experience with this. When I visited San Miniato, I don't remember anyone checking you on the way in about clothes, etc. It's not like some churches where there is a man at the door. This may be your experience too, so you may be able to bring food in without a problem. I'd suggestgo a little hungry (which after hiking up to San Miniato you will be!) and if someone does turn you away, eat your meal first and then visit the church. Otherwise tour the church first and then eat.

Monks chant during vespers and the public is welcome (check the schedule) Here is somebody's video http://vimeo.com/1027551 Pz Michelangelo is well covered by Google Maps Street View so you can take a look at its potential for being a picnic site.

off topic, but this is a great hike to make at dusk. The view, as you will see, is quite grand.

Hi Yvonne, That sounds a great idea. I dont think you would have a problem carrying food into the church (I didnt) as long as it is in a carry bag etc, and not obvious, but personally I would have my picnic dinner outside the church rather than the piazzale, which is usually busy.
There is a gravel area in front of the church where you can sit on the top of the wall and eat and an area to the right of church which has park bench seats and although there were no tables, we perched our food between us on the bench. Both areas give outstanding views of the city. Such a lovely spot. Enjoy.