Step 1Quarter 2 of the onions. Combine the water, beef, beef bones, the quartered onions, the peppercorns and cinnamon stick in a stock pot or large soup pot. Bring to a rolling boil over medium-high heat. With a slotted spoon, skim off the foam. Reduce the heat to medium. Cover and cook until the beef is tender and the broth is fully flavored, 2 1/2 to 3 hours. Season with 2 teaspoons of the salt. Strain. Reserve the meat and refrigerate for another use. Refrigerate the broth 2 hours or overnight.
Step 2Remove and discard the fat. Bring the broth to a boil, and reduce by one-fourth. This should take about 30 minutes. Set aside.
Step 3Heat 2 tablespoons of the oil in a large skillet over medium heat. Fry the almonds, shaking the pan occasionally, until light gold, 2 to 3 minutes. Transfer to a bowl and set aside.
Step 4Slice the remaining onions and add them to the same skillet with 1 tablespoon of the oil and 2 tablespoons of the broth. Cover and cook until the onions turn soft, 10 to 15 minutes. Add the sugar, 2 teaspoons of cinnamon and 1 teaspoon of salt. Partially cover and continue to cook, stirring occasionally, until the onions acquire a deep caramel color, 1 1/4 to 1 1/2 hours. Add the raisins and heat. Set aside.
Step 5Meanwhile, prepare the couscous. Bring 2 1/4 cups of the broth, the remaining 2 tablespoons of the oil and the remaining teaspoon of salt to a boil in a saucepan. Remove from the heat. Add the couscous in a stream. Stir once. Cover, and set aside until the couscous is tender, 5 to 7 minutes.
Step 6Reheat 2 cups of the reserved beef broth. Combine 1/2 cup of the broth with the orange blossom water and mix with the couscous. Mound the couscous on a warm serving platter. Spoon the onion mixture around the base. Garnish with spokes of fried almonds. Sprinkle with powdered sugar and a pinch or two of cinnamon. Serve with the remaining broth on the side.