Tas Kebab (Meat Stew with Vegetables)

0 Prepare the spice mixture: In a small bowl, combine 2 tablespoons olive oil, tomato paste, dried lime powder or lemon juice, advieh, paprika, oregano, ½ teaspoon black pepper, 1 teaspoon salt, and turmeric. Add 1½ cups water and whisk until smooth. Set aside.
1 Sauté the onions: Heat the remaining 2 tablespoons olive oil in a 4-quart cast-iron casserole dish, braiser, or wide Dutch oven over medium-high heat. Add the onions and sauté until softened and lightly golden, about [timer minutes=10]10 minutes[/timer]. Tip: Add a pinch of salt when the onions are half cooked. This will help draw the moisture out of the onions and brown faster.
2 Brown and partially cook the meat: Add the lamb and brown on all sides, stirring occasionally, about [timer minutes=5]5 minutes[/timer]. Add the garlic and cook for [timer minutes=1]1 minute[/timer], until fragrant. Season with the remaining ½ teaspoon black pepper and ½ teaspoon salt. Add 1 cup water and stir to combine. Increase the heat and bring to a boil. Cover, reduce the heat to low, and simmer until the meat is about 50% cooked, stirring once or twice, about [timer minutes=45]45 minutes to 1 hour.[/timer] The cooking time will vary depending on the type and size of the meat.
3 Meanwhile, preheat the oven to 350°F (175°C).
4 Layer the vegetables: Once the meat is about 50% cooked, arrange the vegetables over the meat in this order: sliced peppers, tomatoes, carrots, and potato chunks. Tuck the bay leaves between the vegetables. Pour the prepared spice mixture evenly over the vegetables. Do not stir.
6 Finish cooking: Cover the pot and transfer it to the middle rack of the oven. Cook for [timer minutes=45]45 minutes to 1 hour[/timer], or until the meat is tender and the vegetables are cooked through. The sauce should be thickened and bubbling around the edges of the pot. Drizzle the saffron water over the stew during the final [timer minutes=10]10 minutes[/timer] of cooking. Taste and adjust the salt, dried lime, or lemon juice as needed.
7 Serve: Remove the pot from the oven and let the stew rest for a few minutes. Garnish with fresh herbs, if desired, and serve warm.