In a large saucepan, melt the butter over medium-high heat. Add the onions and cook until soft, about 3 minutes. Add the garlic, and cook, stirring, for 30 seconds. Add the potatoes, marjoram, salt, and pepper, and cook, stirring, for 1 minute. Add the stock and bring to a boil. Reduce the heat to medium-low and simmer, stirring occasionally, for 15 minutes. Add the watercress and cook until the potatoes are tender, about 10 minutes.

Remove from the heat and puree with a hand-held immersion blender, or in batches in a food processor or blender. Add the cream and return to medium heat. Cook, stirring occasionally, until heated through, adding more cream, if a thinner soup is desired. Adjust seasoning, to taste.

Drape each potato pancake wedge with a slice of smoked salmon, topped with 2 teaspoons of sour cream, and 1/2 teaspoon of salmon caviar. Serve with soup.

Grate the potatoes and squeeze between towels to dry.

Heat 2 tablespoons of the oil in a large skillet over medium-high heat. Toss the potatoes lightly with salt and pepper and add in batches to the skillet, pressing down with a spatula to form a cake. As the potato cake starts to crust on the bottom, cover, and cook over medium-low heat until brown and crusty on the bottom, about 7 to 10 minutes. Flip the potato cake and add the remaining oil to the pan. Cook until the cake is brown on the second side and cooked through, about 5 minutes.

Remove from the pan and cut into 6 wedges.

Yield: 6 servings