In a small saucepan, combine white wine, white wine vinegar, granulated sugar, and a pinch of salt. Heat gently until the sugar dissolves completely.

In a small bowl, dissolve powdered gelatin in 1 tbsp of water. Let it bloom for 5 minutes.

Stir the bloomed gelatin into the warm wine mixture until fully dissolved. Pour the mixture into a shallow dish and refrigerate until set, about 2 hours.

Arrange the smoked salmon in a flower-like shape on a serving plate. Add watercress as garnish.