Heat the oil in a large, lidded pan and cook the onion, garlic and aubergine for 5 minutes to soften and brown slightly.
Stir in the harissa paste, tomatoes, chickpeas and stock, bring to the boil and cook for 4 minutes.
Stir in the couscous and cook for 1 minute, then season.
Make 4 hollows in the mixture and crack an egg into each. Cook for 10-12 minutes, or until the eggs are set. Remove the lid for the last couple of minutes.
To serve, squeeze over the lemon juice and scatter the parsley.