Shake everything except ginger beer, strain into an ice filled Collins glass, top with ginger beer.
So Matt doesn't remember the recipes for the ingredients, so I'll take a swing at them. For the gin, I'd either use something like Small's that is super cardamom, or infuse a tablespoon of lightly crushed green cardamom pods into a London Dry gin until it's flavored. For the turmeric syrup, I would think it's a 2:1 simple with the addition of 1 teaspoon of grated turmeric per each cup of sugar. For the tamarind jam, dissolve tamarind paste with barely enough hot water to remove fibers and seeds, then add sugar back to it to make it thick and jammy.