Recipe adapted from Sarah Copeland's forthcoming book, "Feast" (Chronicle Books).
1/4 cup agave nectar
1/2 cup water
3/4 cup thinly sliced sorrel leaves
4 limes, quartered, plus 4 thin rounds, for garnish
40 ounces seltzer, chilled
Splash of gin (optional)
Combine agave nectar and water in a small saucepan. Bring to a simmer over medium heat, stirring. Let syrup cool completely, then transfer to a blender and puree with sorrel until smooth. Pour syrup through a fine sieve into a bowl and discard solids.
Squeeze lime quarters into a large pitcher. Add quarters to pitcher and gently smash with the back of a wooden spoon to release the oils in the rind. Add sorrel syrup and seltzer. Serve over ice, garnished with lime rounds and other garden-inspired herbs.