Make a quick simple syrup. In a small saucepan, combine 1 cup water with the sugar.
Warm over medium heat, stirring, until the sugar fully dissolves. Remove from heat and let it cool slightly. This ensures smooth sweetness without graininess.
Juice the lemons. Roll each lemon on the counter with your palm to loosen the juice.
Cut and squeeze until you have 1 to 1¼ cups lemon juice. Strain out seeds and most pulp if you prefer a cleaner texture.
Blend the strawberries. Add hulled strawberries to a blender with ½ cup water. Blend until very smooth.
For a silkier lemonade, strain the puree through a fine-mesh sieve to remove seeds; for extra body and fiber, skip straining.
Combine in a pitcher. In a large pitcher, pour in the lemon juice, strawberry puree, and the cooled simple syrup. Add 2 to 3 more cups of cold water and stir well. Taste and adjust—add more water for a lighter drink, more lemon for tang, or a touch more syrup for sweetness.
Chill and serve. Refrigerate for at least 30 minutes, or add plenty of ice to chill quickly.
Serve over ice with lemon slices, strawberry halves, and a few mint leaves if you like.
Optional sparkle. For a fizzy twist, top each glass with a splash of sparkling water instead of adding it to the whole pitcher. This keeps the bubbles lively.