Watercress Soup

My mother always waxed rhapsodic about watercress, she'd tell tales of how she and my grandmother would gather watercress in the creeks around their home, of the peppery flavor added to tea sandwiches and salads. Now, my grandmother was a tenacious woman, not afraid to get her hands dirty, but somehow I have a hard time picturing my grandmother's Chanel lapel pins tromping around in a stream.

Nonetheless, I always pick up some watercress when it's in season as if compelled by my mother's tales, but I have often found the leaves were thick and tough, or far too peppery to eat as part of a salad. But this year I spied in my grocery a delicate plant of tiny green leaves, with its root ball preserved in a small container of water. Watercress is a fascinating organism- it thrives on the edge of streams, where it has to have constantly flowing water to protect it from parasite and snails. Watercress can quickly become wilted and bitter once removed from fresh water, which explains those many unappetizing specimens I'd had in the past.

After a few pleasing crunchy salads, I turned the rest of the watercress into a pleasingly simple soup, one thickened with potato and a splash of cream, and bright green like a Shrek cartoon. It's simple in the way many good things are, you could serve it cold like a vichysoisse, or I like it warm with a nice hunk of toast.

Watercress Soup

olive oil, salt
1 large bunch watercress, leaves only, discard the stems
1 medium sweet yellow onion, peeled and diced
1 medium russet potato, peeled and roughly chopped
water or vegetable stock, about 4 cups
splash of heavy cream, optional

1. In a large saucepan, heat the olive oil over medium high-heat. Cook the onions, stirring until browned and caramelized, at least 15 minutes.
2. Pour in the water or stock, add the potatoes, season with salt, and bring to a boil. Let simmer until the potatoes are tender when pierced with a fork. If the water level gets low, add some more. When the potatoes are tender, toss in the watercress leaves and stir until wilted and bright green, a few minutes.
3. Remove the pot from the heat and allow to cool slightly. Place in a blender (or using an immersion blender), blend until very smooth. Add the cream if desired, and taste for seasoning. Reheat before serving.