Yield: Makes 4 first-course servings
1) Purée two thirds of tomatoes and half of peaches with ice, shallot, 1 tablespoon oil, 1 tablespoon vinegar, 2 teaspoons tarragon, 3/4 teaspoon salt, and 1/4 teaspoon pepper in a blender until very smooth, about 1 minute. Force through a medium-mesh sieve into a large glass measure, discarding solids. Stir in water to desired consistency.
2) Toss together remaining tomatoes and peaches with remaining tablespoon oil, remaining 1/2 tablespoon vinegar, remaining teaspoon tarragon, and remaining 1/4 teaspoon each of salt and pepper in a bowl.
3) Serve soup in bowls topped with tomato peach salsa.