Start by making your strawberry puree. Place all the ingredients in a blender or food processor, and puree until smooth. Strain through a fine mesh sieve and refrigerate until ready to use. (You’ll have a little more than a cup of puree, which is enough for roughly 8 cocktails.)
Add the tequila, lime juice, and strawberry puree to a copper mug or tall glass. Mix with a swizzle stick (or spoon) until well combined. Fill the mug/glass with ice. Add the ginger beer and a splash of club soda (if using), and stir to combine. Bottoms up.