Heat the oil in a large saucepan and fry the onions quickly until browned. Then add the garlic and brown that lightly.
Add the aubergine and brown lightly too.
Add the spices, chopped parsley and coriander, tomatoes, tomato puree and all the vegetables except the courgettes. Bring up to the boil and then turn down heat and cook slowly over a very low heat for about ½ hour. Alternatively, cook in oven 180ºC/350°F/gas mark 4 for the same length of time. The vegetables should be al dente. If the mixture is too dry, add a little water.
Now add the courgettes as these cook more quickly than the other vegetables.
Season with salt and pepper and cook for a further 10 minutes or until the courgettes are tender.
Brown the almonds and sesame seeds in the oven, microwave or frying pan.
When ready to serve, remove the vegetable tagine from the stove or over and sprinkle the browned almonds and sesame seeds over the top.
Serve either with couscous or rice and hand harissa around separately.