1 or 2 tablespoons olive oil
1 large rib celery, cut into small dice (1/4 cup)
1/2 medium yellow onion, cut into small dice (1/2 cup)
2 1/2 pounds ripe tomatoes, cored and cut into wedges, then seeded
1 1/2 tablespoons unflavored gelatin powder
1/2 cup heavy cream
Leaves from 6 sprigs tarragon, chopped (2 or 3 tablespoons)
Salt and freshly ground black pepper, to taste
Heat the oil in a medium saute pan over medium heat. Add the celery and onion; cook, stirring occasionally, for about 5 minutes, until softened but not browned.
Add the tomato wedges and stir to incorporate; cover and cook for 15 minutes, stirring once or twice to break up tomatoes, then uncover and cook for 10 minutes, so that some of tomatoes' moisture evaporates. (But if tomatoes look too dry during the last 10 minutes of cooking, put lid back on pan.)
Pass mixture through fine disk of a food mill, or press it through a fine-mesh strainer into a medium bowl. Discard solids. Return strained mixture to pan; reduce heat to medium-low and stir until heated through. Consistency should be that of tomato sauce; add water as needed if it is too thick, or cook longer if it is too thin. Remove from heat.
Combine the gelatin and 1/4 cup hot water in a small bowl, stirring until dissolved. Let it sit while you use a whisk to whip cream in a separate bowl, until it is slightly thickened.
Add the tarragon, dissolved gelatin and whisked cream to tomato mixture in pan; stir to incorporate. (There should be about 4 cups total.) Season with the salt and pepper to taste.
Pour mixture into a 4-cup-capacity terrine or gelatin mold. (Alternatively, mixture can be divided among martini glasses.) Refrigerate for 8 hours, or until set. Terrine can be made a day in advance.
When ready to serve, carefully run a knife around inside edge of terrine or mold. Immerse bottom of terrine or mold in a large bowl or a sink filled with a few inches of hot water for 30 seconds, then place a plate over top. Invert so terrine unmolds onto plate.
Cut into slices to desired thickness; transfer to individual salad plates with dressed greens. (Or place filled martini glasses on individual plates.) Serve chilled with a dollop of chilled guacamole on top.
Makes 6 to 8 servings.
— Recipe from Lloyd Ronick, Rockville, Md., third-place winner in The Washington Post's Top Tomato contest.