1. Place [A] in a pot and heat. After boiling, simmer on medium heat for 2-3 minutes, remove the dashi packet, and let it cool.
2. In a bowl, beat the egg gently, add the cooled dashi and heavy cream, mix well, then strain into serving bowls.
3. Place the bowls in a pot with water up to half the height of the bowls, cover with a lid, steam on high heat for 1 minute, then reduce to very low heat and steam for about 8 minutes, ensuring no bubbles form.
4. Once steamed, let it cool to room temperature, then chill in the refrigerator.
5. Before serving, garnish with boiled baby corn, edamame, and prosciutto.
   

Tip: For a fluffy finish, ensure to mix the egg without creating foam. Use chopsticks to break the egg yolk and whites by moving the chopstick tips side-to-side at the bottom of the bowl, then scoop up with the chopsticks.