1

Preheat oven to 200°C or 180°C fan-forced. Lightly spray a 20cm square ovenproof dish with oil. Arrange one-third of the potato over base of dish, overlapping slices slightly. Spread half the onion over the potato. Repeat layering with remaining potato and onion, finishing with a layer of potato.

2

Pour stock into dish and sprinkle with thyme. Season with salt and freshly ground black pepper. Cover with foil and bake for 20 minutes. Uncover, lightly spray top with oil and bake for 40 minutes or until potato is crisp and golden.

3

Meanwhile, lightly spray a flameproof baking dish with oil and heat over medium-high heat. Cook beef, turning, for 3–5 minutes or until browned. Season with salt and freshly ground black pepper. Bake for 20 minutes for medium-rare or until cooked to your liking. Transfer to a plate. Cover with foil and set aside to rest for 5 minutes before slicing thickly.

4

Place baking dish (with remaining juices) and oil over medium heat. Add eschalots and cook, stirring, for 5 minutes or until softened. Add garlic and cook for 1 minute. Add wine and cook for 2 minutes or until reduced slightly. Stir in stock and bring to the boil. Reduce heat and simmer for 5 minutes or until thickened. Stir in vinegar, butter and sugar. Season with salt and freshly ground black pepper.

5

Divide potato bake and beef among plates and serve drizzled with sauce.