Traditional Lablabi is made with soaked but uncooked chickpeas, which extends the cooking process to several hours. This recipe uses already cooked or canned chickpeas to shorten the time. The key spices are caraway and harissa for authentic flavor depth. The soup must be extremely hot when served to crush the bread and partially cook the egg.
In a large pot, heat the olive oil. Add the chickpeas, water/broth, most of the garlic and caraway, salt, and pepper.
Bring to a boil, then reduce the heat and let it simmer for at least 30 minutes to allow the flavors to meld. If you want a thicker soup, mash some of the chickpeas.
While the soup is simmering, prepare the topping paste: Mix the remaining raw garlic, caraway, 1 tbsp of olive oil, and harissa. The mixture should be spicy.
Cut the bread into small pieces and divide it among four deep bowls. Spread some of the harissa-garlic paste over the bread.
Ensure the soup is extremely hot. Pour the soup into the bowls directly over the bread (about 2 parts soup to 1 part bread).
Make a well in the soup and, if desired, crack a raw egg into it. The heat of the soup will partially cook it.
Garnish with chunks of tuna, capers, olives, and drizzle with extra olive oil and lemon juice. Serve immediately while the bread absorbs the liquid.