Tear the crusts off the White Bread and soak the pieces briefly in a little Water until completely softened, about 2–3 minutes; then squeeze out and reserve any excess liquid.
Place the drained bread in a food processor or large bowl and add the Tarama. If you don't have a processor, mash together with a fork until well broken down.
Finely grate or very finely chop the Onion and add it to the mixture along with the Lemon Juice. Pulse or mix until the mixture is combined and starting to become creamy.
With the processor running (or while vigorously whisking by hand), slowly drizzle in the Extra-Virgin Olive Oil so the mixture emulsifies into a light, fluffy spread. Continue until you reach a smooth, spreadable consistency.
If the dip seems too thick, add a teaspoon or two of the reserved soaking Water and blend again until you get the desired creaminess.
Season to taste with freshly ground Black Pepper; taste before adding salt because the Tarama is often already salty. Adjust lemon or oil as needed for balance.
Transfer to a serving bowl, chill for at least 30 minutes to let flavors meld, then serve with bread, pita, or raw vegetables.
