Preheat your oven to 220°C/200°C fan/gas mark 7.
Remove the steaks from your fridge to allow them to come up to room temperature.
Chop the potatoes into 2cm chunks (no need to peel). Pop them onto a large baking tray. Drizzle with oil, season with salt and pepper, then sprinkle over the dried rosemary.
Toss to coat, then spread out in a single layer. TIP: Use two baking trays if necessary.
When the oven is hot, roast on the top shelf until golden, 25-35 mins. Turn halfway through.

Meanwhile, halve, peel and chop the shallot into small pieces. Halve any thick broccoli stems lengthways.
Peel and grate the garlic (or use a garlic press).
Pick the tarragon leaves from their stalks and roughly chop (discard the stalks).

Heat a drizzle of oil in a small saucepan on medium-high heat.
Once hot, add the shallot and cook, stirring, until softened, 3-4 mins.
Add the garlic, stir-fry for 1 min more, then transfer to a bowl and allow to cool.
Once cooled, add the butter to the shallots and mash with a fork to combine. Stir through the tarragon, then set your Bearnaise butter aside.

When the potatoes have 10 mins left, put a large saucepan of water with 1/4 tsp salt on to boil for the broccoli.
Heat a drizzle of oil a large frying pan on high heat. Season the steaks with salt and pepper.
Once hot, lay the steaks into the pan and fry until browned, 1 min on each side. Lower the heat slightly and cook for another 1-2 mins on each side if you want them medium-rare. TIP: Cook for 1-2 mins more if you like it more well done. IMPORTANT: Wash your hands and equipment after handling raw meat. The steak is safe to eat when the outside is browned.

Once cooked, transfer the steaks to a plate. Spread over the Bearnaise butter, cover loosely with foil and allow to rest for a couple of mins.
Meanwhile, add the broccoli to the pan of boiling water and cook until just tender, 3-5 mins.
Once cooked, drain in a colander, then return to the pan. Drizzle with a little oil and season with salt and pepper.

When everything's ready, cut the steaks widthways into 2cm slices. Transfer to your plates, spooning over any melted buttery juices from the plate.
Serve with the herby potatoes and broccoli alongside.
Enjoy!