Whisk together smoked paprika, oregano, salt, cayenne pepper & black pepper with olive oil and lemon juice in a large mixing bowl. Mix in the chicken thighs until completely coated, then tightly cover and marinate in the fridge for as long as you have time for (2 - 24 hours). If you're pushed for time just marinate at room temp whilst you prep the other ingredients.
In a large deep baking tray combine potatoes, peppers, onion, chorizo, rosemary and garlic with a light drizzle of oil and a pinch of salt & pepper. Nestle in the chicken thighs (skin side up) and brush with any leftover marinade. Ensure the potatoes are all visible to allow them to crisp, then make sure the chorizo is more hidden to prevent it from burning. Place in the oven at 200C/400F for 30mins.
Remove from the oven, flip the potatoes and baste the chicken with the juices in the base of the pan. Evenly scatter over the olives, tomatoes and orange zest, then place back in the oven for another 15mins, or until the chicken is piping hot through the centre and lightly charred/crisp on top. The tomatoes and olives should be slightly wrinkled with the potatoes soft all the way through.
Evenly divide everything for serving, then whisk the liquid left in the pan to combine the fats & juices. This is bonus flavour! Plus the garlic will be buttery soft, do with that what you will.