Preheat oven to 180°/200°C or 350°/400°F fan.
Make the pickles by adding the red onion to a bowl along with the juice of 1 to 2 limes and a big pinch salt. Scrunch all together and set aside.
Add all of the marinade ingredients into a bowl, and stir well. Have a taste. It should be spicy, sweet, salty, and slightly acidic. Make any changes you see fit.
Lay the baby tomatoes out on a lined baking tray, and drizzle them with olive oil and salt.
Nestle the chicken pieces around the tray, and coat each piece with the harissa marinade.
Sprinkle a touch more of salt all over the chicken, and place the tray in the oven for about 45 minutes, until the chicken is golden brown and caramelised.
Meanwhile, make the chickpea stew by heating a good glug of olive oil to a large frying pan, on medium heat.
Gently cook the onions down for about 5 minutes before adding the garlic and sautéing until softened and golden.
Add the spices and stir.
Add the chickpeas and the chicken stock, and simmer for about 30 minutes, until thickened and reduced.
Add the juice of 2 limes and a big dollop of greek yoghurt, and stir to combine.
Season to taste. If it needs salt then definitely add.
To plate, tip the chickpeas onto a platter, and spread out to create a bed for the chicken. Top with the chicken and tomatoes. Drizzle over a few generously spoonfuls of that gorgeous gravy from the baking tray, and finish with a generous scatter of the limey pickled red onions and another squeeze of lime.
