Heat up the oil in a large pot set over a medium heat.
Add the chicken thighs, season them with salt and pepper, and fry for 2-3 minutes on each side.
Add the sliced chorizo to the chicken, and fry it on both sides for 1 minute.
Remove the chicken and chorizo from the pot and set aside.
In the same pot, add the peeled and chopped onion and garlic, and fry them until golden.
Add the chopped tomatoes, and give everything a good stir.
Place a lid on the pot, and leave the tomatoes to cook for 2-3 minutes until they are mushy.
Add the paprika, tomato paste and chilli flakes, mix well, then add the rinsed rice to the pot.
Give everything a good stir, add the chicken and chorizo back to the pot, add the black olives and pour over the chicken stock.
Place the lid on the pot and leave everything to cook until all the liquid is absorbed.
Remove the pot from the heat, but keep the lid on for a further 10 minutes for the rice to become nice and fluffy.
Garnish with chopped parsley.