Grate the russet potatoes and yellow onion, then soak in salted water for 20-30 minutes.

Drain the mixture and dry thoroughly using a kitchen towel.

Combine drained mixture with beaten egg, matzo meal, salt, and pepper to form latke batter.

Heat vegetable oil in a skillet and fry latkes for 6-10 minutes per side until golden brown.

Poach eggs in simmering water with vinegar for 4½ to 5 minutes until whites are set.

Blend egg yolks, lemon juice, and salt; slowly drizzle in melted butter while blending until thickened.

Assemble by placing a latke on a plate, topping with smoked salmon or other protein, and poached egg. Drizzle with hollandaise and garnish.