Could be alot of things...marjoram, cress, or Mexican oregano.
The definititve thing would be what did it taste like.
Linda C

Eileen.....Could it be watercress?

Look at this link and scroll down to the last picture at the page bottom. It's a very small-leaved herb and they say it resembles clover.

SharonCb

Here is a link that might be useful: Gourmet Herbs

I'm thinking it is cress also - but not watercress. The English and Europeans often sprinkle on fresh cress as a garnish in the same manner we use fresh parsley. The cress can be bought in a little container at the store or you can grow it on a windowsill from seed. Watercress is cultivated and grows best with its feet in water.

It tasted kinda like arugula it does look like watercress in a miniture version..Im gonna have to call the restaurant as im curious now..this is a high end place so it could be a number of things.

Fully mature watercress has a larger leaf than clover but the young shoots are tiny and do have a peppery taste. And yes, it is a water lover. I grow mine in the stream of my pond as they do the best in flowing waters. Both large and small leaves are very good in salads, on sandwiches and as a garnish. If you have enough of it, it makes a wonderufl soup, both warm and cold with shrimp or scallops.