India, June 14 -- On a warm summer afternoon in Kolkata, I was served what looked like a perfectly ripe mango. But as I took my first bite, I realized this was no ordinary fruit-it was a dessert, shaped and shaded with such delicacy that it could fool the eye. Inside, it was layered with light mousse, soft sponge, and a delicate fruit core. Everything was edible, except for the tiny green leaf resting on top. It was beautiful, it was complex, and it was unforgettable.

This moment was my introduction to Lille, the dessert bar that's quietly transforming Kolkata's sweet scene-and at the heart of it all are two remarkable siblings: Karishma and Viraj Kothari.

Karishma, just in her twenties, is the creative soul of Lille. Born and raised in K...