Mache

Mâche (mache) has rounded dark green leaves and is used in salads or steamed and eaten as a vegetable. The flavor is slightly nutty with a subtle tang. It was named corn salad because it was found growing in cornfields in the U.S. Before using make sure to wash it well and allow it to dry completely. Store refrigerated in airtight bags. Tends to be hard to find, try your local farmer's market.

If you don't have mache you can substitute:
>>>Butter lettuce (mild)
OR>Watercress (peppery)