We grow a variety of Brassicas through the year.  In the tunnels and glasshouses we are lucky to be able to produce greens through the year, mainly thanks to the hardy Brassica family!  The Brassica leaves that make up the 'Brassica Packs' that often feature in our veg boxes are typically oriental greens, like Mitzuna, Namenia, Radish Leaf, Pac Choi, Tatsoi, Taisai, Komatsuna, Texel Greens, Chrysanthemum and a wide variety of mustard greens. 
The Brassica Packs differ from season to season, sometimes they contain smaller leaves, and at other times the more sturdy shoots, but they are always tender and tasty and there is no waste as all the leaf can be eaten.
To prepare the leaves, wash and spin dry as you would a salad.  Chop and either lightly steam or stir fry, or simply heat up a dressing and toss into the greens, to wilt them slightly.