Traditional Vietnamese Herbal Cooling Drink

Rinse all dried herbs (Sâm leaves, longan, chrysanthemum flowers) under cold water to remove any dust or impurities. Gently knot the pandan leaves to release more flavor.

In a large pot, combine the rinsed herbs, knotted pandan leaves, and 2 liters of water. Bring the mixture to a boil over medium-high heat.

Once boiling, reduce the heat to low, cover the pot, and let it simmer gently for 20-25 minutes. This allows the herbal essences to fully infuse into the water.

Add the rock sugar to the pot and stir until it completely dissolves. Taste and adjust sugar if desired.

Remove the pot from the heat. Carefully strain the liquid through a fine-mesh sieve into a clean pitcher or heatproof container, discarding all the cooked herbs.

Let the Nước Sâm cool to room temperature, then refrigerate until thoroughly chilled. Serve cold, optionally over ice.