Heat 1 teaspoon oil in a nonstick skillet over medium-high heat. Add oregano and garlic, and saute 30 seconds. Add vinegar, and remove from heat. Combine vinegar mixture and beans in a bowl. Cover and chill 30 minutes.
Add 1 teaspoon oil, diced tomato, and the next 5 ingredients (tomato through pepper) to bean mixture, and toss well. Serve with Crostini.