Score a cross into the skin of the tomatoes and place in a bowl. Pour over enough boiling water to cover the tomatoes and leave to sit for 30 seconds. Pour the boiling water away and plunge the tomatoes into cold water. The skin should now be easy to peel away. Peel and then dice the flesh.
Heat a tablespoon or so of oil in a large frying pan or shallow casserole dish. Peel the onion and chop into half moons. Add a pinch of salt and fry over a medium low heat until softened and slightly golden, about 10 minutes.
As the onion fries, prepare the other ingredients. Chop the chicken thighs into bite-sized pieces, season with salt and pepper and fry in a separate frying pan until golden (but not cooked through), about 5 minutes.
Chop the asparagus into 2-inch lengths. Chop the courgette in half lengthways and cut into thick slices. Remove the chicken from the pan. Add the veggies to the pan the chicken was cooked in, season with salt and pepper and fry briefly until golden, 2-3 minutes.
Once the onion is softened, add the minced garlic to the pan. Cook, stirring constantly, for 1 minute. Add the spices and continue to stir for a minute. Add the diced tomatoes, chicken stock and cinnamon stick and simmer for 5 minutes.
Add the chicken, vegetables and preserved lemon to the sauce and continue to simmer for about 10 minutes, until the chicken is cooked through and the vegetables are tender. Taste and season according to your preference - you may not need to if you stock was salted. Serve with cauliflower cous cous.
Cauliflower cous cous
Heat oven to 200C (400F). Break the cauliflower down into florets. Put the florets into your food processor and pulse until it resembles cous cous. (You may need to do this in batches depending on the size of your food processor). Place the cous cous in a large mixing bowl. Season with salt and drizzle with a tablespoon of oil. Mix well with a fork and then spread out on a baking sheet. Bake for 10-15 minutes, turning halfway, until lightly golden.
If you don't have a food processor you could make the cauliflower cous cous by grating the cauliflower on a box grater - takes longer but it works!