Rub the steaks with the garlic and a little salt and pepper. Place on the upper rack of the halogen oven. Set the temperature to 250°C (482°F) and cook for 3 minutes on each side. (Cook a little longer if you prefer your steaks well done.) Remove from the oven and leave to rest in a warm place while making the sauce.
Remove the rack from the oven and add the butter to the bowl. Cook briefly at 200°C (392°F) until melted. Add the shallots and cook for 3 minutes. Stir in the cream and sorrel, and cook for 5 minutes until heated through. Season to taste with salt and pepper, and spoon over the steaks. Serve with chunky chips.