Creating Mary Berry Beef Casserole is a breeze with this simple step-by-step guide:

1. Preheat Oven: Preheat your oven to 325°F (160°C).
2. Brown the Beef: Heat the vegetable oil in a large ovenproof casserole dish over medium heat. Brown the beef cubes in batches, ensuring they’re nicely seared on all sides.
3. Sauté Onions and Garlic: Once the beef is browned, remove it from the pot and set it aside. In the same pan, sauté the chopped onion and minced garlic until soft.
4. Add Vegetables: Stir in the sliced carrots and chopped celery. Cook for a few minutes until they begin to soften.
5. Incorporate Tomato Paste and Spices: Add the tomato paste, dried thyme, and bay leaf. Stir everything together and cook for another minute.
6. Return Beef to Pot: Place the browned beef back into the casserole dish. Season with salt and pepper.
7. Add Liquids: Pour in the beef stock and red wine, making sure to scrape any browned bits from the bottom of the pan.
8. Bring to a Simmer: Bring the mixture to a gentle simmer on the stovetop, then cover the casserole with a lid.
9. Bake: Transfer the casserole to the preheated oven and bake for 2 to 2.5 hours, or until the beef is tender and the flavors meld together beautifully.
10. Thicken Sauce (optional): If you prefer a thicker sauce, remove the casserole from the oven and stir in the flour. Return to the oven for an additional 15-20 minutes.
11. Garnish: Once done, remove the bay leaf and sprinkle chopped fresh parsley over the casserole for a touch of color.

These steps will guide you in preparing a hearty and wholesome Mary Berry Beef Casserole that’s sure to impress!