Soak the dried kokum pieces in 1 cup of warm water for at least 30 minutes, or until soft. Squeeze the softened kokum to extract all its juice and color into the water. Strain the liquid through a fine-mesh sieve into a bowl, discarding the solid kokum pieces. This concentrated liquid is your 'Agal' or kokum extract.

In a large mixing bowl, combine the prepared kokum extract (Agal), thick coconut milk, chopped green chili (if using), crushed garlic (if using), grated ginger (if using), cumin powder, black salt, regular salt, and sugar.

Whisk all the ingredients together thoroughly until well combined and the sugar and salt have fully dissolved. Taste and adjust the seasonings as needed, adding more salt, sugar, or a squeeze of lime if you desire. If the consistency is too thick, you may add a little cold water to reach your preferred texture.

Cover the bowl and refrigerate the Sol Kadhi for at least 1-2 hours. This chilling period is crucial for the flavors to meld and for the drink to be served at its most refreshing temperature.

Before serving, give the Sol Kadhi a quick stir. Pour into individual glasses, garnish generously with fresh coriander leaves, and serve immediately. Enjoy this traditional Konkan digestive drink chilled, especially during warm weather.