Recipes for harissa vary according to the household and region. Variations can include the addition of fermented onions or lemon juice. Prepared harissa is sold in jars, cans, bottles and tubes. Harissa is sometimes described as "Tunisia's main condiment", even "the national condiment of Tunisia", or at least as "the hallmark of Tunisia's fish and meat dishes". In Tunisia, harissa is used as an ingredient in a meat (poultry, beef, goat, or lamb) or fish stew with vegetables, and as a flavoring for couscous. It is also used for lablabi, a chickpea soup usually eaten for breakfast.
In 2006, the Tunisian production of harissa was 22,000 tonnes, incorporating about 40,000 tonnes of peppers. Tunisian harissa is often made with chilis grown around Nabeul and Gabès, which are relatively mild, scoring 40,000-50,000 on the Scoville scale.
In Algeria, harissa is commonly added to soups, stews, and couscous. Harissa paste can also be used as a rub for meat or eggplants. Another significant producer is Algeria's Annaba Province, which is also a significant consumer. According to cookbook author Martha Rose Shulman, premade harissa tastes rather different from that which is served in Tunisian and expatriate restaurants.
Moroccan cuisine has also adopted harissa, using it as a side condiment for tagines, or sometimes mixed into dishes. Tunisia is the biggest exporter of prepared harissa.