This is a classic cocktail here in Glasgow served at the Rogano Oyster bar. It's essentially a margarita variation but far more of a crowd pleaser and a nice way to introduce drinks with a chilli kick.
25ml Reposado Tequila
50ml fresh lemon juice
Splash of St Germain
2-8 slices of red chilli depending on taste and strength of chilli.
Muddle slices of red chilli in the bottom of the shaker. In my experience doubling the number of chilli slices more than doubles the kick so do be careful. Add all other ingredients to shaker and fill with ice. Shake vigorously and double strain into a chilled martini glass and garnish with the remaining chilli.