* Place all ingredients from tequila to ice cubes in a cocktail shaker or lidded jar/bottle and give it a good shake. Give it a quick taste so you can can adjust anything if required - lemon juice/tequila or spices.
* Mix some chaat masala and red chilli powder in a small plate and keep ready for the rim.
* Take 2 glasses - stemmed cocktail glass or old-fashioned - moisten the rims with a wedge or lemon. Rotate these rims in the chaat masala-chilli powder mix.
* Divide the cocktail mix between the two glasses and top with club soda. Garnish with a mint sprig and a slit whole red chilly before serving.
PS: this is a great cocktail for a party pitcher. Make the basic mix in the pitcher and top each glass individually with the soda and garnish just before serving.
Variation: You can even pour over crushed ice, or freeze the whole mix and blend to a slushy consistency to make it more like a spicy, Indianised Guavarita.