Tasty veg tagine

1 red onion, chopped 2 garlic cloves, chopped fine A little olive oil ½ tsp ground cumin  ½ tsp ground coriander  ½ tsp ground cinnamon 1 red pepper , seeded and chopped 1 courgette , chopped 1 aubergine, chopped 4 vine tomatoes , chopped 400 g tin chickpeas, rinsed and drained 250 ml vegetable stock  2 tbsp harissa …