Heat a paellera at low heat and add chorizo. Sauté for about 2 minutes or until golden and put aside.
Add oil to the pan. Pat dry the pork dices, season with salt and pepper, and sauté until golden. Put aside.
Pat dry chicken, season with salt and pepper, and brown over medium-high heat. Remove and set aside.
Season prawns with salt and pepper and sauté until they turn pink. Remove and set aside.
Pat squid dry, season with salt and pepper, and sauté quickly until they just gain some color. Remove and set aside.
Add the red-bell pepper strips and heat until golden. Set aside.
In the same paellera, add the garlic and onions and sauté until soft at medium-low heat for 2-3 minutes. Add the tomatoes and the diced peppers, and rosemary and cook at medium-heat for about 15 minutes or until the mixture is dry.
In a large pot, bring about 1 cup of water to a boil. Steam the mussels or clams on a rack for 4-5 minutes for the mussels or about 6-10 for the clams until they open. Strain broth, add 6 cups chicken stock, saffron threads, and reserve (make sure to keep broth warm). Set aside the mussels or clams, getting rid of the ones that did not open.
9. Stir in rice and let cook for 2-3 minutes. Add chorizo, pork, squid, and chicken.
Measure 7 cups of the reserved broth. Add to the paellera and cook for about 10 minutes at medium-heat or until the liquid starts to evaporate. Transfer to the oven and cook for another 10 minutes.
Remove pan from the oven and arrange the shellfish on top of the rice. Cover with cloth and let sit for 10 minutes. Garnish with reserved pepper strips, serve immediately.