Finely chop the onion using a food processor.

Finely chop the celery ribs and garlic using a food processor.

In a thick-bottomed pot, sauté the chopped onion in olive oil over medium heat until soft and sweet.

Stir in the tomato paste, harissa, paprika, caraway, and ground coriander.

Season with salt and pepper to taste.

Mix all the spices and pastes well with the onions.

Add the chopped celery and garlic to the pot and stir to combine.

Pour in 4 cups of water and stir thoroughly.

Bring the mixture to a boil, then reduce heat to low and simmer for 20 minutes.

Add the semolina to the soup and stir continuously to prevent lumps.

Continue to simmer for another 10 minutes, stirring occasionally.

Scoop out the flesh from the lemon.

Coarsely chop the lemon flesh.

Add the chopped lemon to the soup and simmer for a final 5 minutes.