Ingredients

Makes 4 main-course servings

　　6 oz small boiling potatoes

　　1 1/4 teaspoons salt

　　1/4 cup fresh lemon juice

　　2 tablespoons drained bottled capers, rinsed and finely chopped, plus additional whole capers for sprinkling

　　1 1/2 teaspoons Dijon mustard

　　1 1/2 teaspoons sugar

　　1/2 cup extra-virgin olive oil

　　1 small red onion, halved lengthwise, then very thinly sliced crosswise

　　1 firm-ripe California avocado

　　1/2 seedless cucumber (usually plastic-wrapped), thinly sliced crosswise

　　3/4 lb thinly sliced smoked salmon

　　1/2 lb sliced pumpernickel bread, cut into triangles

　　

Step 1

Peel potatoes and cut into 1/4-inch-thick slices, then transfer to a 2-quart saucepan and cover with water by 1 inch. Add 1/2 teaspoon salt and bring to a boil. Reduce heat and simmer, partially covered, until potatoes are tender, 5 to 8 minutes. Drain, then transfer to a bowl.

　　

Step 2

Meanwhile, whisk together lemon juice, chopped capers, mustard, sugar, and remaining 3/4 teaspoon salt until sugar and salt are dissolved, then whisk in oil until emulsified.

　　

Step 3

Toss potatoes gently with 1/4 cup dressing. Toss onion with 1/4 cup dressing in another bowl and let stand 5 minutes.

　　

Step 4

Peel and pit avocado, then cut into 1/4-inch-thick slices.

　　

Step 5

Arrange potatoes, avocado, cucumber, onion, salmon, and bread on a large platter and sprinkle with whole capers. Drizzle with some dressing and serve remainder on the side.