How to Make It
In a medium saucepan, cover the rice with the water and bring to a boil. Cover and cook over low heat for 13 minutes. Remove from the heat and let the rice steam, covered, for 5 minutes. Lightly fluff the rice and cover.
Meanwhile, in a deep skillet, cook the bacon over moderate heat until crisp; transfer to paper towels. Pour off all but 2 tablespoons of the fat in the skillet. Add the onion, celery, thyme and 1/8 teaspoon of the cayenne. Cover and cook over moderately low heat, stirring, until the onion is softened, 7 minutes. Add the stock and bring to a simmer over moderately high heat. Add the rice and bacon and stir well. Remove from the heat, season with salt and pepper and cover.
In a bowl, combine the flour with 1/2 teaspoon of salt, 1/4 teaspoon of pepper and the remaining cayenne. In another large skillet, heat 1/4 inch of vegetable oil until shimmering. Pat the livers dry with paper towels, dredge in the flour mixture and add to the skillet. Cover with a splatter screen and fry over high heat until browned outside and rosy within, about 1 1/2 minutes per side. Transfer the livers to a plate and sprinkle lightly with salt.
Transfer the rice mixture to a platter. In a bowl, toss the watercress with the pickled onions and olive oil. Season with salt and pepper. Arrange the watercress and livers over the rice and serve.
To pickle, soak 1 thinly sliced small red onion in 1/2 cup vinegar with 1/4 cup sugar and a pinch of salt for about 1 hour.