How to Make It
Place tomatoes in a colander and let drain 30 minutes.
While tomatoes drain, whisk together cream, orange zest, orange flavoring, and 1/4 teaspoon of the salt just until stiff peaks form, about 2 minutes. Stir in 2 tablespoons of the walnuts. Chill orange cream until ready to use.
Transfer drained tomatoes to a large bowl. Add cherries, tarragon, honey, walnut oil, pepper, 1 teaspoon of the sherry vinegar, and remaining 2 tablespoons chopped walnuts and 3/4 teaspoon salt. Transfer tomato mixture to a colander and let drain 5 minutes.
Place a 3-inch metal ring mold on a plate. Fill ring with 1/2 cup of the tomato mixture; smooth top. Remove ring. Repeat procedure with remaining tomato mixture on a total of 6 plates. Drizzle 1/4 teaspoon of remaining sherry vinegar on top of each tartare. Place a quenelle or dollop of orange cream on top of each tartare. Garnish with tarragon leaves. Serve immediately.