Place the goat cheese and cream in the bowl of a food processor, mix until smooth. Add zest, lemon juice and poppy seeds. Close with a film and refrigerate for 1 hour. Carefully sort the berries, rinse and dry. Put them in a deep bowl, add mint, orange and lemon juice, shake lightly. Arrange the berries in the center of a serving dish, arrange the washed, dried watercress leaves in a circle and drizzle with the dressing.