Some days, all that is required is a simple roast with veg. We've cooked the beef to a rare finish in this recipe, leave it in the oven a little longer, if you like. However you like it cooked, remember to let it rest for about 10 minutes before slicing.
1.Preheat oven to 220°C/200°C fan-forced. Cover base of large shallow baking dish with the thyme.
2.Trim excess fat from beef; tie with kitchen string at 3cm intervals. Brush beef all over with a little of the oil, sprinkle with pepper. Cook beef in heated large frying pan until browned all over; place on thyme in baking dish.
3.Toss potato with remaining oil then place around beef; roast, uncovered, in oven, about 25 minutes or until beef is cooked as desired.
4.Meanwhile, for horseradish mayonnaise, blend egg yolks and juice until smooth. With motor operating, add oil in a thin, steady stream until mayonnaise thickens. Add horseradish; blend until combined. Transfer to medium bowl; stir in chives. Adjust consistency by stirring in a little hot water. Cover; refrigerate until required.
5.Remove beef from dish; discard thyme. Cover beef tightly with foil. Spread potato in single layer in baking dish; roast, uncovered, until golden and tender.
6.Slice beef thickly; serve with mayonnaise and potato.
Homemade mayonnaise is not hard to make, and it’s well worth the effort. The secret is to add the oil very slowly, drop by drop, until it starts to thicken. Then you can add the oil in a slow steady stream. It should take several minutes to add all of the oil. If time is short, buy a good-quality whole-egg mayonnaise and flavour it to your taste with some lemon juice, prepared horseradish and finely chopped chives. We used desiree potatoes, however, pontiac and sebago are also good. There is no need to peel them. Serve with steamed baby peas.