Prepare the Jameed (if using dried): If you have dried jameed, you'll need to rehydrate it. Break the jameed into smaller pieces. Place them in a large bowl and cover with warm water (about 1 liter / 4 cups). Let it soak for at least 8-12 hours, or overnight, changing the water once or twice if possible. The jameed should soften considerably. Once softened, whisk it vigorously with a fork or a whisk until it forms a smooth paste. You can also blend it for an even smoother consistency. If using the yogurt alternative, skip this step and proceed to step 4, adding the yogurt later.

Cook the Lamb: In a large, heavy-bottomed pot or Dutch oven, place the lamb pieces. Add the quartered onion, bay leaves, and cardamom pods. Pour in enough water to generously cover the lamb, about 2.5 liters (10.5 cups). Bring to a boil over medium-high heat, then immediately reduce the heat to low. Skim off any foam or impurities that rise to the surface during the first 10-15 minutes of simmering. Cover the pot and let the lamb simmer gently for about 1.5 to 2 hours, or until it is very tender and almost falling off the bone. Add salt and turmeric during the last 30 minutes of cooking. Carefully remove the lamb pieces from the pot and set them aside. Strain the lamb broth through a fine-mesh sieve into a clean bowl or pot, discarding the solids. You should have at least 1.5 liters (6.3 cups) of rich broth.

Prepare the Yogurt Sauce: In a large saucepan, combine the rehydrated jameed paste (or the plain yogurt mixed with lemon juice if using the alternative) with about 1 liter (4 cups) of the reserved lamb broth. Whisk vigorously to combine. Place the saucepan over medium heat. Stir constantly to prevent the yogurt from curdling. This is the most critical step: you must keep stirring until the sauce comes to a gentle simmer and thickens slightly. Do NOT let it boil rapidly, as it can curdle. If using the yogurt alternative, cook for about 15-20 minutes, stirring constantly, until it thickens. If using jameed, simmer for about 30-40 minutes, stirring constantly, until it reaches a sauce-like consistency. Add more lamb broth if the sauce becomes too thick. Taste and adjust seasoning with salt if needed, but be cautious of the jameed's saltiness.

Cook the Rice: Rinse the basmati rice under cold running water until the water runs clear. Drain well. In a separate pot, melt the ghee or butter with the vegetable oil over medium heat. Add the drained rice and sauté for 2-3 minutes, stirring gently, until the grains are coated and lightly toasted. Add 750ml (3 cups) of water (or broth if you prefer, for extra flavor) and a pinch of salt. Bring to a boil, then reduce the heat to the lowest setting, cover tightly, and cook for 15-20 minutes, or until the water is absorbed and the rice is tender. Let the rice rest, covered, off the heat for 5-10 minutes before fluffing with a fork.

Assemble the Mansaf: To serve, traditionally, a large, round, flatbread (shrak or khubz) is placed on a large communal platter or serving dish. Spoon the cooked rice evenly over the bread, pressing it down slightly to create a base. Arrange the cooked lamb pieces over the rice. Generously ladle the warm yogurt sauce over the lamb and rice, ensuring everything is well-coated. If the yogurt sauce seems too concentrated, you can mix in some of the reserved lamb broth or a little plain yogurt to achieve a more fluid consistency.

Garnish and Serve: Sprinkle the toasted slivered almonds and pine nuts generously over the top of the Mansaf. Garnish with freshly chopped parsley. Serve immediately while hot. Traditionally, Mansaf is eaten with the hands, using the right hand to scoop portions of rice, lamb, and sauce together. Offer extra plain yogurt on the side if desired.