To make the stock: In a very large stock pot, combine the chicken stock and water with the onions, carrot, celery, leek, ginger, garlic, tarragon, parsley, jalapenos, annatto seeds, juniper berries, peppercorns, and sea salt. If the rabbit kidneys and heart are available, add the heart to the stock and reserve the kidney for later. Bring to a boil over high heat, then reduce the heat so that the stock is simmering and skim any foam from the top. Simmer for 15 minutes, partially covered, then add the rabbit. Simmer for 45 minutes to 1 hour, or until the meat is tender. Don't allow the stock to come to a rolling boil, otherwise the rabbit will be tough. The different cuts of meat will take different times to cook, so test for doneness and when each joint is tender, remove it to a plate with tongs. When cool enough to handle, remove the meat from the bones and cut it into large chunks. Discard the bones and set the rabbit meat aside on a plate.
Strain the stock through a colander, pressing down on the all the vegetables to extract as much flavor as possible. Wash the pan and strain the stock back into it, this time through a strainer
lined with a double thickness of slightly dampened cheesecloth. If necessary, add water to make the level of stock up to 8 cups.
In a large heavy casserole, heat the lard over high heat. Add the orzo and cook, stirring constantly, until the pasta is golden, about 4 minutes. Add the paprika and the achiote paste mixture, mashing it well to break it up, and cook for 1 minute more. Reduce the heat to medium low, add the onion and cook for 4 to 5 minutes, or until softened. Add the garlic and salt and cook for 1 minute more, until the aroma of the garlic is released. If using the kidneys, coarsely chop and add them to the pan, then add the stock and bring to a simmer. Simmer for 15 minutes, uncovered, stirring occasionally all the way down to the corners of the pan to keep the orzo from sticking. Add the rabbit with all its accumulated juices, and the peas and cook for 5 minutes more. Taste for seasoning and serve, scattered with chopped parsley.
Achiote paste is a bright orange seasoning paste from the Yucatan made from ground annatto seeds, oregano, cumin, cinnamon, pepper and cloves. It is often thinned with vinegar or citrus juices for marinades and sauces and should always be cooked first to remove any chalkiness. This is what produces the bright orange color often found in Mexican food, so be sure to wash off any utensils that touch it or they just might remain orange. The paste is sold in bricks in Mexican markets and can be kept well wrapped in the refrigerator for a long time.