Ingredients

2 teaspoons fresh lemon juice

1/2 teaspoon coarse salt

Freshly ground pepper

2 teaspoons extra-virgin olive oil

3 cups (about 4 ounces) baby arugula

1 small red onion, halved and cut into paper-thin half-moons

Preparation

Put lemon juice, salt, and pepper in a medium bowl. Whisking constantly, pour in oil in a slow, steady stream; whisk until emulsified. Add arugula and onion; toss.