Tomatoes are a woefully underutilised cocktail ingredient. Particularly at their peak of ripeness, they add acidity and brightness to a drink, as well as a beautifully vegetal note that plays well with a large range of ingredients. 

Ingredients
1/4 ounce gin
2 ounces dry vermouth
1 1/2 ounces tomato water (see below)
Club soda, chilled, to top
Prosecco, chilled, to top

Garnish: cherry tomato, halved
Garnish: parsley stalk

Make your Tomato Water
Add 1 container plum tomatoes into a juicer and mash them. Allow the mixture of tomato juices and skins to sit, refrigerated, for 30 minutes to an hour, in order for the juices to pick up the aroma from the skins.
Add the mashed tomatoes into a strainer and allow to drip into a container until all the juice is collected.

To make the Spritz
Add all ingredients except club soda and prosecco into a highball glass filled with ice and stir to combine.

Top with equal parts club soda and prosecco, and stir again briefly and gently to combine.

Garnish with a halved cherry tomato and a parsley stalk.