Soak the Dried Chickpeas overnight in plenty of cold water (or do a quick boil-soak if short on time), then drain and rinse before cooking.
In a large stockpot place the drained chickpeas with the Beef Shank, whole Chicken, the Jamón Serrano Bone, the Beef Marrow Bone and Pork Belly. Cover with cold water (about 3–4 liters), slowly bring to a gentle boil and skim any foam that rises.
Season the pot with a couple of Bay Leaf, a teaspoon of Black Peppercorns, a generous pinch of Salt and the Saffron Threads (steep them in a little warm broth first if you can). Reduce heat and simmer gently for 1½–2 hours, until the chickpeas and meats are tender.
About 40 minutes before the end of cooking, add the prepared vegetables: sliced Leek, halved Onion and chopped Carrot so they soften and absorb the broth.
At roughly 30 minutes remaining add the Spanish Chorizo to the pot whole, and add the Morcilla de Cebolla in the final 20–25 minutes so it heats through without disintegrating. Also add the Potato and roughly chopped Green Cabbage and cook until just tender.
When everything is cooked, remove the chicken and bones from the pot. Strain the broth into another pot and keep it hot. Strip the meat from the Jamón Serrano Bone and the Chicken, and slice the Pork Belly and Beef Shank for serving.
To make the traditional soup course, heat a little Olive Oil in a small saucepan, sauté minced Garlic briefly until fragrant, stir in a teaspoon of Sweet Paprika, add about 2 cups of the hot strained broth and toss in a handful of Fideo Noodles; simmer until the noodles are tender — this yields a flavorful starter broth.
Arrange the chickpeas, vegetables and sliced meats on a large platter or serve in warmed bowls; ladle additional hot broth over them or serve the broth separately as desired. Taste and adjust seasoning with more Salt if needed.
Serve the cocido with plenty of Crusty Bread for sopping up the broth and some Pickled Guindilla Peppers on the side to add a bright, piquant contrast.
