Preheat your oven to 200°C/Fan 180°C/Gas 6. Scrub the potatoes and slice them into bite-sized chunks. Remove any leaves from the beetroot, scrub the beetroot and cut it into 1cm-thick slices.

Tumble the potatoes and beetroot into a large roasting tin. Toss with 1 tbsp olive oil and a pinch of salt and pepper. Slide the veg into the oven to roast for 20 mins.

Meanwhile, peel the red onion and slice it into thin wedges. Set aside.

Spoon half the pot of crème fraîche into a bowl. Stir in 1 tbsp horseradish mustard and set aside.

When the beetroot and potatoes have cooked for 20 mins, add the red onion to the tin. Turn the veg over and return to the oven for 15-20 mins, till everything is tender.

While the veg roast, pour 1 tbsp olive oil into a large frying pan and warm to a high heat. Rub a little salt and pepper into the minute steaks. When the pan is smoking hot, add the steaks and fry for 30 secs-1 min on each side, then lift them out onto a plate and set aside to rest for 3-4 mins.

Peel and finely chop the garlic. When the veg are roasted, remove the tin from the oven and add the garlic. Pour over 1 tbsp balsamic vinegar and stir. Fold in the watercress.

Divide the roast veg between a couple of warm plates and dollop over the horseradish crème fraîche. Slice the steaks and lay them on top. Squeeze over the juice from 1 lemon half to serve.