Preheat Oven to 375°F (190°C)

Step 1. Sear the Meat:

• In a large fry pan, heat the clarified butter. Once hot, add the beef chunks and season them with salt and black pepper. Sear the beef chunks in batches until they have a golden-brown crust from the Maillard reaction. Avoid overcrowding the pan to ensure proper browning.
  
• Remove the seared beef and set aside.

Step 2. Prepare the Aromatics:

• In a large Staub Dutch Oven or oven-safe dish, sauté the diced bacon over medium heat until it starts to render its fat. Add the chopped onion and cook until light golden brown.
  
• Incorporate the fresh thyme, rosemary, and sliced garlic; sauté until fragrant.

Step 3. Add the Tomatoes, Guinness Beer, and the Seared Beef:

• Add the drained tomatoes, Guinness beer, leeks, celery, and carrots to the pot. Introduce the reserved seared beef and pour over the beef stock.
  
• Add the prunes and adjust salt and pepper to taste.

Step 4. Simmer then Slow Cook in the Oven::

• Bring the mixture to a simmer, then cover with a lid. Transfer to the preheated oven and let it cook for about 2.5 hours.
  

Step 5. Thicken the Stew:

• Around 45 minutes before the stew is ready, remove it from the oven. The beef should start to be more tender but not yet fall apart when tested with a fork.
• Gradually stir in the prepared roux (or enough flour) to thicken the stew to your preference. Ensure the flour is well incorporated.
  
• Return the pot to the oven and continue cooking until the stew reaches your desired thickness, and the meat falls apart easily when tested with a fork.

Step 6. Serve and Enjoy!

• Serve the stew hot, accompanied by a generous portion of mashed potatoes. Garnish with fresh herbs and, if desired, additional prunes for a unique touch.

  Here is a link to my Garlic Butter Mashed Potatoes recipe
  
• Enjoy your meal!