Begin by grating the russet potatoes and yellow onion using a box grater or food processor. Soak in salted water for 20-30 minutes, then drain and squeeze out moisture.

Combine the drained potato and onion with a beaten egg, matzo meal, salt, and pepper in a mixing bowl until just moistened.

Heat a skillet over medium heat with about ¼ inch of vegetable oil. Form the latke mixture into 3-inch rounds and fry until golden brown, 6-10 minutes on each side.

In a separate saucepan, bring water with white vinegar to a simmer. Poach eggs for 4½ to 5 minutes until whites are set and yolks are soft.

Blend egg yolks and lemon juice until thick, then slowly whisk in melted butter to create a hollandaise sauce.

Assemble by placing a latke on each plate, topping with a poached egg, smoked salmon (if using), and hollandaise. Garnish with chives and pepper.