1. Combine tomatoes, 1/3 cup chives, 1 tablespoon garlic, vinegar, 3/4 teaspoon salt, and pepper in a large bowl; let stand 15 minutes. Drain mixture in a colander over a bowl, reserving liquid.
2. While the tomatoes stand, bring 2 quarts water to a boil in a large saucepan. Add 1 tablespoon salt and pasta. Cook the pasta for 10 minutes or until al dente, and drain.
3. Heat butter, olive oil, and remaining 1 1/2 tablespoons garlic in a large skillet over low heat; cook 4 minutes or until fragrant. Increase the heat to medium-high. Add reserved tomato liquid, and bring to a boil; cook until reduced to 1/2 cup (about 6 minutes). Add clams; cover and cook 4 minutes or until shells open. Remove clams from pan, and discard any unopened shells. Add reserved tomato mixture and pasta to pan; cook for 2 minutes or until thoroughly heated. Top with the remaining chives.
Sustainable Choice: Because they help filter the water in which they live, clams and other bivalves are sustainable superstars.