Add chopped strawberries to a large measuring glass. Muddle or mash into a pulp with the back of a spoon. Add ginger beer, tequila and lime juice and stir to combine. Fill two copper mugs with ice. Divide tequila mixture among mugs and top up with sparkling water. Garnish each mug with a fresh strawberry and serve.
For a spicy kick, muddle fresh cilantro and two slices of jalapeño with the strawberries.