Heat 6 tablespoons of the oil in a large skillet over medium heat. Add the onions and 1 teaspoon of salt and cook, stirring frequently, until caramelized and deep golden brown, about 30 minutes. Transfer the onions to a large bowl. Add the prunes, apricots, figs, walnuts, sugar, and cinnamon. Stir until fully combined and season with salt and pepper to taste.

Preheat the oven to 375°F. Rub the potatoes, turnips, and butternut squash with the remaining 2 tablespoons of oil, then toss the vegetables with the turmeric. Season well with salt and pepper. Spread the vegetables evenly in a large roasting pan. Spoon the fruit-nut mixture over and around the vegetables.

Add 1½ cups of water to the pan. Roast the vegetable mixture until well browned and cooked through, stirring them once halfway through cooking for even browning and adding more water if needed, about 1 hour.

While the vegetables are roasting, toast the almonds in a dry medium skillet over medium-low heat, stirring often, until lightly browned, about 6 to 8 minutes. Set aside.

Transfer the vegetables and fruit-nut mixture to a large serving platter and sprinkle with the toasted almonds. Serve immediately.