In a large bowl place the cucumber, red peppers, tomatoes and lemon juice. Cover with cold water, and salt the water as you would for pasta. Let the bowl sit on the counter for 30 minutes, or overnight in the refrigerator. Discard the water, and blend the cucumbers, peppers and tomatoes with the watermelon in a food processor. Press the mixture through a strainer, then transfer the mixture to a blender and blend until smooth adding the vodka and then the sherry vinegar, to taste. With the blender running add the oil in a thin thread until the mixture changes color (turning orange.) Chill the mixture before serving.
NotesThis recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.