Step 1: Start with the Potatoes
Begin by preheating your oven to 220°C/200°C fan/gas mark 7.
Take the steaks and butter out of the fridge, allowing them to come up to room temperature.
Next, halve the salad potatoes widthways and place them on a baking tray. Drizzle the potatoes with oil and season them with salt and pepper. Toss them to ensure they’re evenly coated, then spread them out in a single layer on the tray, with the cut side facing down.
Step 2: Finish the Potatoes
Once your oven is at the desired temperature, roast the potatoes on the top shelf for about 20 minutes.
After 20 minutes, remove the potatoes from the oven. Gently crush each potato half using the bottom of a bowl or pan.
Give the smashed potatoes another drizzle of oil and place them back on the top shelf of the oven. Continue roasting until they turn crispy and golden, usually for about 10-15 minutes.
Step 3: Make the Tomato Butter
While the smashed potatoes are roasting, place the butter in a small bowl and mash it with a fork until it becomes soft and spreadable.
Finely chop the parsley, including the stalks, using the amount specified in the ingredients.
Combine the sun-dried tomato paste and half of the chopped parsley with the mashed butter. Set this tomato butter aside.
Step 4: Fry the Steaks
When the potatoes have about 8 minutes left to cook, heat a drizzle of oil in a large frying pan over high heat. Season the steaks with salt and pepper.
Once the pan is hot, carefully lay the steaks in it. Fry each side for about 1 minute to achieve browning. If you prefer medium-rare, continue to cook for an additional 1-2 minutes on each side. If you prefer more well-done, cook for an extra 1-2 minutes per side.
Transfer the cooked steaks to a plate, top each with a portion of the tomato butter, and loosely cover them with foil to rest.
Step 5: Get Started on the Spinach
While the steaks are resting, return the same frying pan to high heat, adding another drizzle of oil.
Once the oil is hot, add the spinach in handfuls until it wilts and becomes piping hot. This usually takes 2-3 minutes.
After wilting the spinach, stir in the wholegrain mustard and season everything with salt and pepper to taste.
Step 6: Finish and Serve
When the smashed potatoes are ready, take them out of the oven. Toss them with the mustard spinach to combine flavours.
Slice the rested steaks widthways into thick slices and serve them alongside the mustard smashed potatoes.
For the finishing touch, spoon the sun-dried tomato butter from the resting plate over the steaks, and then sprinkle the remaining chopped parsley on top.
With your dish fully prepared, it’s time to enjoy your delicious meal!