For the rice: In a medium saucepan, combine the rice, coconut milk, 1 cup water and the salt. Bring to a boil over medium-high heat, then reduce the heat, cover and simmer until the liquid has been absorbed, about 15 minutes.
For the chicken filling: Heat the oil in a large nonstick skillet over medium heat. Add the coriander, cumin, salt, black pepper, garlic and shallots and cook, stirring constantly, until the garlic and shallots have softened, about 2 minutes. Stir in the coconut milk and sugar and bring to a boil. Add the chicken and stir to coat with the sauce. Cook, stirring occasionally, until the sauce has thickened, about 5 minutes.
For assembly: Preheat a nonstick grill pan over medium-high heat. Layer the 2 halves of a Swiss chard leaf perpendicular to each other on a cutting board to create a cross shape. Spoon 2 tablespoons of the rice into the center where the leaves meet and flatten the rice into a rectangle. Layer 2 tablespoons of the chicken filling evenly over and top with an additional tablespoon of rice to cover the chicken. Fold the top and bottom of the Swiss chard leaf over the filling to make a small square package. Repeat with the remaining leaves, rice and chicken.
Grill the packages in batches until the leaves are charred on both sides, about 5 minutes per side. Serve warm.