Preheat your oven to 200°C/Fan 180°C/Gas 6. Pour 1 tbsp olive oil into a large roasting tin and slide it into your oven for a 2-3 mins to warm up. Scrub the potatoes and slice them into bite-size pieces. Remove the roasting tin from the oven and add the potatoes. Season with salt and pepper and stir to coat. Return to the oven and roast for 35 mins, turning halfway.

Meanwhile, trim the bases off the Brussels sprouts and pull away any dry leaves. Halve the sprouts and thinly shred them. Slide the chopped sprouts into a mixing bowl. Peel and thinly slice the red onion and add to the bowl. Peel and finely grate 1 garlic clove and add it to the sprouts. Tip in the rocket. Grate over half of the Parmesan.

Finely grate the lemon zest into a small bowl and squeeze in the juice. Add 1 tbsp olive oil and a good pinch of salt and pepper. Whisk together to make a dressing.

Warm a large frying pan for 3-4 mins till smoking hot. Rub the steaks with 1 tbsp oil and a pinch of salt and pepper. When the pan is smoking hot, add the steaks and cook for 2-3 mins on each side for pink middles, or 2-3 mins longer for well done. Transfer the steaks to a warm plate, loosely cover with foil and rest for 5 mins.

Finely chop the rosemary leaves and grate the remaining garlic clove. When the potatoes have roasted for 35 mins, scatter over the rosemary, garlic and sage leaves. Toss to mix, then return to the oven for 5 mins.

Pour the lemon dressing over the sprout salad and fold together. Grate over the remaining Parmesan. Divide the steaks and potatoes between a couple of plates and serve with the salad on the side.