Prepare the Steak: Pat the beef cubes dry with kitchen paper and season generously with salt and black pepper. This initial seasoning is crucial for building flavour.

Sear the Beef: Heat 1 tablespoon of olive oil in a large, heavy-bottomed, oven-safe pot or casserole dish over high heat until it shimmers. Add the beef in a single layer, ensuring not to overcrowd the pan. Sear for 2-3 minutes on each side until a deep, rich brown crust forms. You'll hear a satisfying sizzle, and the kitchen will fill with the enticing aroma of caramelising meat. Remove the beef and set aside.

Sauté Aromatics: Reduce the heat to medium. Add the remaining 1 tablespoon of olive oil to the pot. Add the chopped onion, carrots, and celery. Sauté for 5-7 minutes, stirring occasionally, until the onions are softened and translucent, and the vegetables are slightly tender. The smell of sweet, cooked onion will start to permeate the air.

Build the Sauce Base: Stir in the minced garlic, dried thyme, and smoked paprika. Cook for another minute until fragrant, being careful not to burn the garlic. The spices will release their warm, earthy notes. Sprinkle in the plain flour and stir well, cooking for 1-2 minutes until it forms a light roux and coats the vegetables. This helps to thicken our sauce later.

Simmer and Combine: Gradually pour in the beef stock, stirring constantly to prevent lumps. Add the tomato purée and the quartered mushrooms. Bring the mixture to a gentle simmer, then return the seared beef to the pot, nestling it into the sauce. The liquid should be bubbling gently and starting to thicken.

Add Potatoes and Cook: Add the halved baby potatoes to the pot, ensuring they are mostly submerged in the liquid. Cover the pot with a lid and transfer it to a preheated oven at 170°C (150°C fan/Gas Mark 3) for 25-30 minutes, or until the potatoes are tender when pierced with a fork.

Finish with Green Beans: Remove the pot from the oven. Stir in the trimmed green beans. Re-cover and return to the oven for another 5-7 minutes, or until the green beans are vibrant green and tender-crisp. You want them to retain a slight bite.

Rest and Serve: Carefully remove the pot from the oven. Let the stew rest, covered, for 5 minutes before serving. This allows the flavours to deepen and the steak to become even more tender. Garnish generously with fresh chopped parsley.