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21 Day Aged Sirloin Steak

21 Day Aged Sirloin Steak

with Mustard Crushed Potatoes, Spinach and Sun-Dried Tomato Butter
4.5(169)
Recipe Development Team
Recipe Development TeamUpdated on June 02, 2026
Calories
602 kcal
Protein
44g protein
Total
40 minutes
Difficulty
Medium
Produced in a facility that processes eggs, milk, fish, peanuts, sesame, shellfish, soy, tree nuts, and wheat.
serving amount

350

Salad Potatoes

1

Wholegrain Mustard

2

21 Day Aged British Sirloin Steaks

30

Sundried Tomatoes

½

Flat Leaf Parsley

30

Unsalted Butter

125

Baby Spinach

Energy (kcal)602 kcal
Energy (kJ)2519 kJ
Fat32 g
of which saturates16 g
Carbohydrate35 g
of which sugars8 g
Protein44 g
Salt2 g
Due to the different suppliers we purchase our products from, nutritional facts per meal can vary from the website to what is received in the delivered box, depending on your region.

Cooking Steps

Get Started
1

Remove the steaks and butter from the fridge to bring them up to room temperature. Submerge the sun-dried tomatoes in a bowl of hot water and set aside. Bring a large saucepan of water with a pinch of salt to the boil for the potatoes.

2

Chop the new potatoes into 2cm chunks (no need to peel). Add the potatoes to the pan of boiling water and cook until you can easily slip a knife through, 12-15 mins. Drain in a colander and set aside when cooked.

Make the Butter
3

Put the butter in a small bowl and mash with a fork until soft. Remove the sun-dried tomatoes from the water, pat dry with some kitchen paper and finely chop. Finely chop the parsley (stalks and all). Stir the sun-dried tomatoes and half the parsley through the butter. Set aside.

4

Put a frying pan on high heat with a drizzle of oil. Season the steaks with salt and pepper. When the oil is hot, lay the steaks in the pan and brown for a 1 minute on each side. Once browned, lower the heat slightly and cook for another 1-2 mins on each side. tTIP: This will cook the steak to medium rare - if you like yours less rare just cook for 1-2 mins more. IMPORTANT: The steak is safe to eat when the outside is cooked. Transfer to a plate, top with the tomato butter and leave to rest.

5

While the steak rests, return the now empty frying pan to high heat with a drizzle of oil. When hot, tip in the drained potatoes and lower the heat to medium. Leave to cook, turning occasionally, until browned at the edges, 3-4 mins. Use a fork to gently crush a few of the potatoes - this will give you lots of delicious crispy edges!

Serve
6

Stir the wholegrain mustard through the potatoes followed by the spinach. Lower the heat and leave for 1 minute to wilt the spinach while you slice the steak. Slice the steak and serve with the mustard smashed potatoes alongside. Spoon over the sun-dried tomato butter (it should have melted while the steaks rest!) and finish with a sprinkling of remaining parsley. Enjoy!

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