Beef & Mushroom Stew with Celeriac Mash

Cube the beef into 2-3 cm pieces if not already done, halve the mushrooms, dice the onions, and mince the garlic. Set aside in separate bowls for easy access during cooking.

Heat a heavy-bottomed pot or Dutch oven over high heat at 200°C, add olive oil, and sear the beef cubes in batches for about 5 minutes total, turning to brown all sides until a deep golden crust forms. Remove and set aside on a plate.

Reduce heat to medium at 160°C, add a drizzle of olive oil if needed, and cook the diced onions for 3 minutes until softened and translucent. Add minced garlic and halved mushrooms, stirring occasionally for 4 minutes until the mushrooms release their liquid and start to shrink.

Stir in tomato paste and cook for 1 minute at medium heat to deepen its flavor, ensuring it coats the vegetables. Return the browned beef to the pot, pour in the beef bone broth, add thyme sprigs, and bring to a gentle boil before covering and reducing to the lowest heat setting at 90°C to simmer for 50-60 minutes, or until the beef is fork-tender.

Peel and chop the celeriac into 2 cm cubes, place in a medium pot, cover with water, add a pinch of salt, and bring to a boil over high heat at 100°C. Reduce to medium heat and simmer for 20 minutes or until the celeriac is soft enough to pierce easily with a fork.

Drain the cooked celeriac thoroughly, return to the pot off the heat, and mash with a potato masher or fork until smooth. Stir in butter, season with salt and pepper to taste, and keep warm until ready to serve.

After simmering, check the beef for tenderness; it should break apart easily with a fork. Remove thyme sprigs, taste the stew, and adjust seasoning with salt and pepper as needed before serving hot.