Eat Local: Wild Rocket and Lettuce Soup
Wild rocket (Diplotaxis tenuifolia) is a weedy cousin of arugula (Aruca sativa) in the Brassicaceae, or mustard, family. It originated in Europe and western Asia and has naturalized in many parts of North America. Its leaves have an untamed, peppery flavor, and its edible flowers have a beautiful yellow hue. In the garden, it grows as a perennial herb given the slightest protection, and it seeds prolifically if allowed. Wild rocket grows rampantly in sandy soils of Long Island, where it blankets roadsides and beach berms with splashes of gold when in bloom in early fall.
If you forage for wild rocket, make doubly sure to harvest in an area where the soil is free from contaminants.(Members of the mustard family are particularly likely to absorb heavy metals.)It grows in clumps of several plants with bushy, erect, branching stems. It is also incredibly easy to grow. It thrives in the sun, but give it a slight bit of shade to encourage a milder flavor, and keep the soil moist so that it stays tender. If it bolts (flowers) early in the season, simply cut it back to encourage a new flush of leaves.
When harvesting, be aware that wild rocket wilts rather easily after picking, especially at midday, but a quick soak in cold water reinvigorates it for use in fresh, uncooked dishes.
The young leaves add a unique flavor tossed into salads with sweet, acidic fruit such as strawberries, raspberries, or even grilled peaches. You can also freeze the leaves for winter pesto: Blanch it first in hot water, then cool it instantly in an ice bath. Drain and wrap it tightly in plastic and place in the freezer. Or enjoy its punchy flavor now in soups, like this one.
Wild Rocket and Lettuce Soup (Hot or Cold)Serves 4
This soup is excellent warm but just as delicious chilled for a refreshing treat on a warm autumn day. The key to success is to use good quality, preferably homemade, stock that has been reduced to concentrate its flavor. This light and uncomplicated soup benefits from a touch of cream and a salty garnish such as bacon, pancetta, fried shallots, or simply a sprinkling of slivered radish. A poached egg to finish wouldn’t be out of order either! If you cannot source wild rocket, simply substitute with domesticated store-bought arugula.
- 1 whole onion, chopped 3 tablespoons salted butter
- 2 cloves garlic, minced
- ¼ teaspoon freshly grated nutmeg
- ½ teaspoon ground coriander
- ½ teaspoon fine sea salt
- 3 cups chicken or vegetable stock
- 1 medium head leafy lettuce, torn
- 2 packed cups wild rocket leaves
- 2 tablespoons cilantro or parsley leaves
- 1½ teaspoons white wine vinegar
- Garnishes (optional)
- Splash heavy cream
- Wild rocket flowers
- Fried pancetta
- Garlic croutons
Place the butter and onions in a large heavy-bottomed saucepan or stockpot. Heat over medium flame, cooking the onions until they become soft and translucent, about 5–7 minutes. Stir in the garlic, salt, and spices and heat until fragrant, about 30 seconds. Add the soup stock and continue to cook with the lid on for an additional 10–12 minutes.
Turn the heat to low and toss in the lettuce, rocket, and herbs. Stir the greens until just wilted, about 2–3 minutes. Turn off the heat and remove from the stove. Stir in the vinegar and carefully transfer the hot mixture in batches to a food processor or blender and process to your desired consistency. Keep some of the texture, or blitz it, beginning on the lowest setting and increasing to the highest, for a smooth, almost creamy soup.
Taste for flavor and add salt and pepper as desired. Serve warm or cold with a touch of cream and the salty garnish of your choice.