2 tablespoons fresh lime juice
1 1/2 teaspoons sugar
3/4 teaspoon salt
1/4 teaspoon black pepper
5 tablespoons extra-virgin olive oil
1 1/4 lb green leaf lettuce (2 heads), trimmed and leaves torn into 2-inch pieces (20 cups)
1/2 lb watercress (2 bunches), coarse stems discarded and sprigs cut into 1-inch pieces (6 cups)
Seeds from 1 large pomegranate (1 1/4 cups), bitter white membranes discarded
3/4 cup sliced almonds (2 1/4 oz), toasted
Whisk together lime juice, sugar, salt, and pepper until sugar and salt are dissolved, then add oil in a steady stream, whisking until combined.
Combine lettuce, watercress, and half of pomegranate seeds in a large serving bowl. Toss with just enough dressing to coat, then sprinkle with almonds and remaining pomegranate seeds.