Mâché Rosettes purchased at Whole Foods were planted in a container and seem to have taken. Once this are double in size they make a great salad.
In France "Mâché" is known as the "Little Sweet One" and used as a salad accompaniment. I love it's tender and slightly nutty flavor and usually add just a bit of rice vinegar and some fresh strawberries.
The tender shoots stand up well to braising or sautéing and are a great side to fish and meat.
When I buy fresh produce I love to look for those that have a bit of their roots still attached. Once at home I plug most of the leaves and leave only about three very young ones. Sometimes I dip the roots in a growth hormone and other times I just try my luck and stick them right into some good potting soil in a semi shaded area. Then I watch over them like a mother hen making sure that the little ones adapt well to their new location.
I guess these little guys liked their spot and pretty soon I can plant more and enjoy the delicate leaves all summer long.
If you prefer to buy them in a store visit Whole foods. Here in the US Mâché is now grown in California by Epic Roots and I am sure they can let you know other places their greens are sold at.