In a large, heavy-bottomed saucepan, heat olive oil to medium heat.
Add garlic and onions and allow to sweat for 4 to 5 minutes by covering the pan. Add the tomatoes and saffron.
Season lightly with salt and pepper. Cover and reduce heat to low. Stir occasionally. When the tomatoes, onions, and garlic are soft, remove and allow to cool in a separate container on ice.
When the mixture is cool, puree in a blender or food processor.
Serve hot or cold, garnished with a drizzle of olive oil.