Warm your chicken stock and stir in the saffron. Set it aside to allow the flavors to infuse. This step is key to achieving that signature golden color and subtle floral taste. Heat the olive oil in a large, deep pan and sear the chicken thighs on both sides until golden brown. Remove them from the pan and set them aside.
This initial browning locks in moisture and ensures tons of flavor. Lower the heat and toss in the chopped onions and red peppers. Cook for about five minutes until softened. Add the sliced chorizo and continue cooking for two minutes until its oils are released, creating a rich base for the dish. Follow up by adding the garlic and cooking for a minute more.
Pour in the vermouth or white wine and bring it to a boil, letting the alcohol evaporate. This step lifts all the flavorful bits stuck to the pan, creating a delicious sauce.
Stir in the tomato paste and paprika, blending everything together. Nestle the browned chicken into the pan alongside the parsley and infused stock. Bring the mixture to a boil, cover with a tight-fitting lid, and reduce the heat to low. Allow the flavors to meld for about 30 minutes.
Once the chicken is tender, stir in the parboiled rice. Cover the pan again and simmer on low for another 15 minutes, or until the rice is fully cooked and has absorbed the liquid. Remove the pan from the heat and leave it to rest for 10 minutes.
Taste and adjust with salt and pepper as needed. Serve the paella directly from the pot or transfer it to a serving dish for a stunning presentation.