Soak the slice of bread in just enough water to be submerged completely. Let it soak for a few minutes. Core the tomatoes and cut them into 1 inch (2 cm) pieces. You don't have to peel them. Using half a tomato, remove the seeds, finely dice and put in a separate small bowl. This will be used as garnish. Put the rest of the roughly chopped tomatoes into the blender.
Take the cucumber, leave the peel, cut off one fourth and finely dice this part. Put in a separate small bowl for garnish. Roughly chop the rest of the cucumber and put in the blender. Do the same with the onion and the red bell pepper; use one fourth to cut into small pieces and put into separate small bowls, chop the rest roughly and add to the blender.
Add the chopped garlic, olive oil, vinegar, salt, pepper, paprika powder and cumin. Take the bread and squeeze out most of the water with your hands and add to the blender.
Blend all the ingredients until smooth in a table top food processor or with a hand mixer. Just give a few pulses if you like a thicker consistency. Add extra water if the soup is too thick and blend again. Add extra seasoning to taste. Put the soup in the fridge and leave it to chill for at least 2 hours.
Serve the soup in a small bowl or glass with the small bowls of diced onions, pepper, tomatoes and cucumber on the side. Taste before serving if you need to add more pepper and salt.