To prepare the simple syrup, combine the strawberries, rhubarb, sugar, 1 cup of water, ginger, and lemon zest in a medium saucepan. Set the pan over medium-high heat and bring the mixture to a gentle boil, stirring now and then. Once it begins to bubble, lower the heat and let it simmer for about 20 minutes or until the fruit is very soft and broken down.

Take the pan off the heat and strain the mixture through a fine mesh sieve into a bowl or large measuring cup. Press gently with a spoon to extract as much liquid as possible, then discard the solids. Stir in the lemon juice and let the syrup cool to room temperature. Once cooled, transfer it to a jar or an airtight container and refrigerate until you're ready to use. It will keep for up to three weeks.

To make a spritz, fill a cocktail shaker with ice. Add ½ cup of the strawberry-rhubarb syrup and ½ cup of your spirit of choice. Secure the lid and shake well until the drink is chilled, about 20 seconds. Strain into two glasses filled with fresh ice. Top each with ¼ cup sparkling water (or more if you prefer a lighter drink).

Garnish with slices of fresh strawberry, ribbons of rhubarb, or a sprig of mint for a refreshing finish. Repeat to make additional servings.