Place tarama and onion in the blender or food processor and blend for 1 minute until the mixture is smooth. Cut the bread into pieces and add in batches, blending all the time.
Add the olive oil gradually through the lid of the blender, followed by the lemon juice, continuing to blend until the mixture is smooth. Add more lemon juice to taste.
7 slices white toast bread, 1 or 2 days old, crusts removed
2 heaped tbsps tarama (fish roe)
1 heaped tbsp finely chopped onion
3/4 cup olive oil
5 tbsps lemon juice