How to Make It
In a large bowl, cover the rice with 2 inches of cold water. Cover with plastic wrap and refrigerate overnight.
In another large bowl, cover the bamboo leaves with cold water. Place a second bowl on top of the bamboo leaves to keep them submerged. Let soak at room temperature overnight.
Drain the rice well and return to the bowl. Add 1 tablespoon of the salt and 1 tablespoon of the sesame seeds and stir to combine.
In a medium bowl, using a rubber spatula, stir the red bean paste with the lemon juice, ginger and a pinch salt until well combined.
Lift 2 bamboo leaves out of the water and pat dry with paper towels. Arrange the leaves on a work surface, overlapping them by about 1 inch. Roll the leaves to form a cone. Spoon 2 tablespoons of the rice into the cone, then 2 teaspoons of the red bean paste and top with 2 more tablespoons of the rice. Fold the bamboo leaves over the opening to form a triangle-shaped bundle. Tie with kitchen string and transfer to a large enameled cast-iron casserole. Repeat with the remaining bamboo leaves, rice and red bean paste, arranging the bundles in a single layer.
Cover the zongzi with 1 inch of cold water. Add a generous pinch of salt. Cover and bring to a boil, then simmer over moderately low heat until the rice is tender and sticky, about 1 hour; add more boiling water if needed to keep the zongzi submerged.
Using tongs, transfer the zongzi to a platter and pat dry with paper towels. Just before serving, discard the string and carefully peel back the bamboo leaves. Drizzle the zongzi with sesame oil and sprinkle with salt and sesame seeds.
Sticky rice (a.k.a glutinous rice), dried bamboo leaves, red bean paste and toasted sesame oil—can be purchased at Asian markets and amazon.com.