Place cut beef in bottom of Dutch oven and season with salt and pepper. Spread sliced onion, peppers, tomatoes, garlic, and thyme on top.
Whisk together water with tomato paste, vinegar, sugar, cumin, Aleppo pepper, salt, and pepper until well combined. Pour liquid into Dutch oven. Cover the pot and bring to a boil over high heat. Transfer to the oven and continue to braise for 2 hours.
Remove lid and increase oven temperature to 425 degrees F. Braise for another 30 minutes, reducing the braising liquid. Remove from oven and season with salt and pepper. Serve Turkish style braised beef with rice or crusty bread.
Notes
If you don't have a Dutch oven, you can use any other type of braising pot. Alternatively, add all of the ingredients to a pot, bring it to a boil, then transfer the ingredients to a 9x13 baking dish. Cover with aluminum foil and continue braising in the oven.