Blend Falsay: In a blending jug, add grewia and water, then blend well.
Strain Mixture: Strain the blended mixture with the help of a strainer into a saucepan and discard the residues.
Cook Mixture: Turn on the flame, add sugar, black salt, and lemon juice, mix well, and cook on medium flame for 4-5 minutes.
Cool Mixture: Let the mixture cool.
Assemble Drink: In a serving glass, add lemon slices, pineapple chunks, and mint leaves, then muddle until it releases juices and becomes aromatic.
Finish Drink: Add 2 tablespoons of prepared grewia puree, ice cubes, and soda water, stir well, and serve!