In a medium bowl, combine the soft goat cheese, cream cheese, chopped sage, lemon zest, and a sprinkle of salt and black pepper. Whip until light and airy, then chill for about 20 minutes.

In another bowl, combine mashed sweet potato, glutinous rice flour, olive oil, and salt. Mix until it becomes a soft, pliable dough. Adjust moisture with warm water if necessary.

Divide the dough into 8 equal pieces. Flatten each piece into a disc, add a dollop of chilled filling, pinch edges to seal, and roll into a smooth ball.

Line a steamer basket with parchment and place mochi balls inside. Steam over medium heat for about 8 to 10 minutes until glossy and firm.

Let the mochi rest for 5 minutes before serving. Garnish with fried sage leaves, a drizzle of olive oil or honey, and sprinkle with flaky salt.