Heat olive oil in a large pot over medium heat. Add the onion and cook until golden, about 5 minutes. Add the garlic and cook for another minute until fragrant.

Stir in the harissa paste, cumin, coriander, and paprika. Cook for 30 seconds until the spices bloom.

Add the chickpeas with their liquid and 2 cups water. Bring to a boil, then reduce heat and simmer for 20 minutes, stirring occasionally, until the broth is flavorful and slightly thickened.

Stir in the lemon juice and season with salt to taste. Place torn bread pieces in the bottom of each serving bowl.

Ladle the hot chickpea stew over the bread. Top with chopped parsley, green onions, an extra drizzle of olive oil, a spoonful of harissa, and a halved hard-boiled egg if desired.