Hi Tilly.
With asparagus it is best to do the flex test. Hold the stem and with both thumbs and forefingers and bend it . It will find it's own breaking part. You eat all of the stalk and "flowery" bit. The rest you discard as it will be woody. I sometimes boil the woody bit to make a stock. It is best undercooked as it is not so nice if it is soft and squashy.
One of my favourite asparagus dishes and is SW friendly is to melt your allowance of Philadelphia light and either use it as a dip for the asparagus or like a bed to sit the asparagus on and serve it with hexb of new potatoes and "gentle" vegetables. You do not want anything that over- powers the asparagus.
I love asparagus and use it in all sorts of ways. It is delicious cooked al dente and layered with cooked potato slices, sweetcorn in an oven proof dish. Pour half a packet of made Coleman's cheese sauce over the dish ( 8 syns) and bake in the oven. I serve this with cauliflower and broccoli and I love it !!!!! Yum, yum.
You will find great info and some fabulous adaptable recipes here
http://uktv.co.uk/food/ingredient/aid/504035