Season beef all over with salt and pepper. Heat 1 tablespoon olive oil in cooker on sauté or in a large frying pan or pot over high heat and sear beef on all sides. Set aside.
Add remaining olive oil, add garlic, celery, carrot, onion and mushroom and sauté until vegetables are starting to colour. Add tomato paste and stir through. Finely chop rosemary and thyme and stir through along with bay leaves and season with salt and pepper. Add beef bone broth, red wine and stir to combine.
Add meat in the centre of the liquid and arrange radishes around it. If using an oven instead of a cooker pour vegetables and liquid in a baking dish with meat in centre and arrange radishes around.
Pressure cook 1 hour or alternatively you can cover your baking dish tightly with foil and bake in a preheated oven at 140C for approximately 3 hours until meat is tender and falling apart.
Remove beef and radishes and add xanthan gum bit by bit, whisking constantly. Add back beef and radishes and serve.