Mix together the tomatoes, red pepper and onion in a large bowl and set aside.
In a small bowl whisk the garlic, allspice, vinegar, pomegranate molasses, olive oil and 1/3 teaspoon of salt, until well combined. Pour this over the tomatoes and gently mix.
Arrange the tomatoes and their juices on a large flat plate. Sprinkle over the pomegranate seeds and oregano. Finish with a drizzle of olive oil and serve.