Heat the oven to 180C (160C fan)/350F/gas 4. Drain the chickpeas and set aside.
Put the onion, garlic, ginger and chilli in a food processor, and pulse a few times until very finely chopped but not pureed, scraping down the sides of the bowl as you go. Add the coriander, and pulse a couple of times more, just to mix through.
On a medium-high flame, heat two tablespoons of oil in a large, heavy-based cast-iron pot with a lid. Add the onion mixture and cook for about four minutes, stirring occasionally, then stir in the cumin, cinnamon, dates and tomato paste, and cook for a minute more, or until fragrant. Add the drained chickpeas, carrots, bay leaves, bicarbonate of soda, 1.2 litres water and a good grind of black pepper, and bring to a boil, skimming off any froth that comes to the surface. Cover and bake for two hours, or until the chickpeas are very soft and the sauce has turned thick and rich. Stir in the lemon juice and two teaspoons of salt, then leave to cool for about 10 minutes.
While the chickpeas are cooking, put the feta in a small bowl with the caraway, lemon zest, parsley and remaining three tablespoons of olive oil, and leave to marinade.
To serve, spoon the feta mixture over the chickpeas and serve directly from the cooking pot.