Place chickpeas, olive oil, lemon juice, tahini, salt, cumin, coriander, sweet, hot, and smoked paprika in the food processor.
Blend until really smooth, scraping the walls of the food processor a few times in between. Add some liquid from the can, little by little, to obtain the desired consistency. Start with about ½ cup and only add more to reach the desired consistency.
Adjust the taste with more salt and lemon juice if necessary.
Transfer to a bowl and sprinkle with nigella seeds before serving.
Notes
The recipe makes 350 g/ 12.4 oz hummus, so one portion would be 35 g/ 1.2 oz. That is one slightly heaped tablespoon of hummus.
Soak the chickpeas overnight or up to 24 hours in plenty of water. Drain, rinse and return to the pot. Cover with plenty of water again, add 1 teaspoon bicarbonate of soda, bring to a boil, and cook, covered, until the chickpeas are really soft; it will take more than one hour, depending on the size and age of the chickpeas.