To make the peach purée, add all the ingredients to your blender and blend on high until smooth.
Transfer the purée to a clean container and refrigerate it until you’re ready to use it. You’ll have enough of the purée to make approximately eight cocktails.
To prepare your glasses, start by spreading some flaky sea salt out onto a small plate.
Moisten the rim of your glasses with fresh lime juice. Then gently press the moistened rim down into the sea salt so that it adheres to the rim of glass. Add ice and set aside.
To make a single cocktail, add the peach purée, tequila and elderflower liqueur to a cocktail shaker with ice.
Shake vigorously.
Then strain into one of your prepared glasses. Top with Prosecco and stir gently. Garnish with sliced peaches and lime. Enjoy immediately.