Wash and hull the strawberries. Cut them in half if they're large and add them to a a large heat-proof bowl. Pour the granulated sugar over the top. Use a potato masher to mask the strawberries and the sugar together until juicy. For a chunkier strawberry lemonade, leave some bits of berries. For a smoother strawberry lemonade, you can puree them with an immersion blender right in the bowl.
Add the hot water. Stir for a minute or so until the sugar is completely dissolved. Add the freshly squeezed lemon juice.
Add the mixture to a pitcher (straining over a fine-mesh sieve if you want a pulp-free lemonade). Stir in the cold water. Taste and adjust the lemon juice or sugar as needed.
Add ice to a glass and pour the strawberry lemonade over the ice. Add fresh sliced strawberries if you like and garnish with a fresh strawberry and/or lemon slice on the rim of the glass, if you'd like.
