Make the sofrito: In a skillet heat 2 tablespoons olive oil. Add the onion and pepper, and cook until softened, about 2 minutes. Add tomatoes, thyme, basil, cumin seed, bay leaf and garlic. Season with salt and pepper. Cook the mixture for 5 to 7 minutes, or until almost all the liquid has evaporated. Set aside.
Pat dry the chicken and season it with salt and pepper. In a large deep ovenproof skillet heat the oil over moderately high heat until it is hot. Add the chicken to the skillet, cook it for 7 to 10 minutes on each side, or until it is browned and transfer it to a plate. Add the sausage or ham to the skillet, cook it, tossing, until it is browned lightly, and transfer with a slotted spoon to the plate.
To assemble the paella: Preheat the oven 400 degrees. In a saucepan bring the broth to a simmer over modertaely high heat, add the saffron or tumeric and let the mixture steep for 5 minutes. In a 14-inch paella pan or a large deep ovenproof skillet, arrange the rice, chicken, sausage or ham and sofrito. Add the prepared broth, bring the liquid to a simmer over high heat, stirring, and immediately remove the pan from the heat. Arrange the shellfish in the pan and bake the paella on the floor of the oven for 25 minutes. (Do not stir the paella during cooking. If the mixture becomes dry, add the additional broth.) Add the peas and bake the paella for 10 minutes more, or until the liquid is absorbed and the mussels have opened. Let the paella stand, covered with a dish towel, for 5 minutes before serving. Serve the paella in its dish garnished with the cilantro and lemon wedges.