Step 1Bring the chicken stock to a simmer in a medium pot. Add the saffron, rabbit and pork, and cook over low heat until the meat is tender, about 1 hour.
Step 2Heat 2 tablespoons olive oil in a skillet over medium-high heat. Add the rice and cook, stirring, until the outside surface of the rice becomes translucent, 2 to 3 minutes.
Step 3Add the pimentón and then immediately add the grated tomato and cook until it thickens, about 2 minutes. The rice will not be tender. Set aside. (The recipe can be prepared to this point up to a day in advance, the ingredients tightly covered and refrigerated.)
Step 4When ready to prepare the paella, start a hot fire in the grill. Remove the rabbit and pork from the stock, reserving the stock.
Step 5Set a 13- to 15-inch paella pan in the center of the grill and add the remaining olive oil. Make sure that the grill sits level so the oil is evenly distributed across the bottom of the pan.
Step 6When the oil is hot, add the rabbit and pork and season lightly with salt. Cook until the meat has lightly browned, about 3 minutes.
Step 7Add the fava beans and artichoke hearts, and cook briefly, stirring constantly.
Step 8Add the rice and tomato mixture and then the reserved stock. Taste the stock and add salt; it should taste fairly salty since the rice is so bland. Keep the fire very hot so you can maintain a boil. Do not stir the rice, but spoon stock over the top of any dry spots.
Step 9Cook until you no longer see liquid bubbling through the rice and the rice is making crackling, popping sounds, 15 to 25 minutes, depending on the size of the pan. Don’t worry if the rice appears to scorch on the bottom or the sides — that is desirable.
Step 10When the rice is done, lay the rosemary stalks on top and cover with newspaper to keep warm. Set aside for 5 minutes before serving.