In a large cocktail shaker, combine mint leaves, diced strawberries, simple syrup, and lime juice.
Use a blunt end muddler to muddle everything together to release mint flavor and mash the strawberries.
Add rum and stir.
Add some ice into two glasses, about half way up, and divide the mixture among the glasses. Make sure the glasses are big enough to fit the mixture and some soda water. (You will need glasses that hold about 12-14 oz.)
Stir the mixture with ice and add club soda and ice.
Stir gently just a few times and serve.
Notes
Muddling Mint: The key is to gently press the mint leaves only about 3 or 4 times with a flat ended muddler (or wooden spoon) to release the mint flavor.
Virgin Mojito: Mojitos have enough distinct flavors to make them virgin washout compromising much of the taste. To make virgin mojitos, simply omit the rum and follow the rest of ingredients and recipe instructions.