In a fine sieve, rinse the rice well under cold running water and drain. In a large, heavy pot, fry the bacon over moderate heat, drain on paper towels, and set aside. Pour off all but 3 tablespoons of the grease, add the onions to the pot, and cook for 3 minutes over moderate heat, stirring. Add the rice and stir well. Add the stock, tomatoes with their juices, lemon juice, Worcestershire, salt, nutmeg, and black and cayenne peppers, bring to a low simmer, cover, and cook for 20 minutes. Stir in the crumbled bacon and the shrimp and continue cooking, uncovered, for 10 minutes, adding a little more stock if the rice seems to be drying out. Stir the bog with a fork, taste for seasoning, and sprinkle the parsley on top.