To cook flat iron steak well, sear it fast over high heat and rest it for five minutes before you slice it thinly against the grain. I tested this method in my own kitchen with supermarket feather steak, and it gave me a tender, juicy steak with a deep brown crust in under 15 minutes. This guide shows you how to cook flat iron steak on the hob, on the grill, and in the oven, with exact temperatures and times for every thickness.
Table of Contents
Key takeaways for how to cook flat iron steak
- Buy flat iron steak, also sold in the UK as feather steak, about 2 cm thick for the best sear.
- Sear it for 2 to 3 minutes per side in a very hot cast iron pan, then rest it for 5 minutes.
- Pull it at 52C for medium rare, 57C for medium, and 63C for medium well, then let carryover heat finish the job.
- Slice it thinly against the grain, or even a well cooked steak will taste tough.
What is flat iron steak, and why is it called feather steak in the UK?
Flat iron steak comes from the shoulder, from a muscle that does very little work, so it stays tender while it still carries plenty of beef flavour. Butchers remove a line of gristle from the centre, which leaves neat pieces that cook evenly. In the UK, butchers and supermarkets often sell the same cut as feather steak, so if you cannot find a pack labelled flat iron, ask for feather steak.
Learning how to cook flat iron steak starts with understanding this cut. I like it because it gives you almost the tenderness of a much pricier cut at a supermarket price. It suits fast cooking and it slices beautifully for sandwiches and salads. It does not suit slow cooking or cooking well done, because the lean meat dries out fast once it passes medium well.
How to buy flat iron steak
Look for steaks about 2 cm thick with a deep red colour and fine white marbling. Avoid steaks cut much thinner than 1 cm, because thin steaks overcook before they can form a crust. A pack of two steaks weighing about 400g feeds two people generously.
Buy it fresh from the butcher counter when you can, and ask the butcher to trim any thick silver skin. Supermarket packs work well too. Keep the steak in the fridge until 30 minutes before cooking, and pat it completely dry with kitchen paper, because a wet surface steams instead of searing.
How to prepare flat iron steak before cooking
Seasoning matters more than a long marinade, so I season generously with flaky sea salt and cracked black pepper just before cooking, or a full hour ahead uncovered in the fridge, which dries the surface and helps the crust.
If you want a marinade, use olive oil, soy sauce, garlic, lemon juice, and black pepper for 30 minutes and no longer than 2 hours. A long soak turns the texture mushy, so keep it short, and wipe off excess marinade before cooking, or the sugars will burn before the meat browns.
Flat iron steak temperature and cooking time
Use a meat thermometer for reliable results, because flat iron steak goes from perfect to overdone in about a minute. Pull the steak 2C below your target, because the temperature rises as it rests.
| Doneness | Pull temperature | Final temperature after resting |
|---|---|---|
| Rare | 48C (118F) | 50C |
| Medium rare | 52C (126F) | 54C |
| Medium | 57C (135F) | 60C |
| Medium well | 63C (145F) | 65C |
For a 2 cm steak, plan on 2 to 3 minutes per side for medium rare, and 3 to 4 minutes per side for medium. A thicker 2.5 cm steak needs about 3 to 4 minutes per side for medium rare.
How to cook flat iron steak in a pan
When you learn how to cook flat iron steak in a pan, the crust matters most, so keep the pan very hot and the steak very dry.
This is my favourite way to cook flat iron steak, because a cast iron pan gives the best crust of any home method. Heat a cast iron pan until it just starts to smoke, add a tablespoon of sunflower oil, lay the dry steak in the pan, and leave it alone for 2 to 3 minutes. Do not move it, because moving it breaks the crust.
Flip the steak once, add a knob of butter, a crushed garlic clove, and a sprig of thyme, and baste it with the foaming butter for the last minute. I tested this butter baste against plain oil searing, and the butter version tasted richer and browned more evenly. Check the temperature, move the steak to a warm plate, and rest it for 5 minutes.
How to cook flat iron steak on the grill
To learn how to cook flat iron steak on the grill, set up two heat zones and keep a thermometer close.
For flat iron steak cooking time on the grill, heat one side of the grill to high heat and leave the other side cooler for finishing. Oil the grill bars, place the steak over direct high heat, and grill it for 2 to 3 minutes per side for medium rare, closing the lid between flips if your grill runs cool in wind. Move the steak to the cooler side if flare ups threaten to char it, and use a thermometer to confirm the pull temperature before resting.
How to cook flat iron steak in the oven
If you want to know how to cook flat iron steak in the oven, use the oven only to finish a pan seared steak.
The oven works best as a finishing step, not as the main cooking method, because a steak cooked only in the oven misses the crust. Sear the steak in a hot pan for 2 minutes per side, then move the pan to an oven heated to 200C and cook it for a further 2 to 3 minutes for medium rare. Use an oven safe pan and check the temperature early.
How to slice flat iron steak against the grain
Once you know how to cook flat iron steak, slicing makes the biggest difference to tenderness, so take a moment to get it right. Look at the steak and find the direction of the long muscle fibres, then cut across those fibres at a slight angle, in slices about 5 mm thick. Cutting with the grain leaves long fibres that feel chewy, while cutting against the grain shortens the fibres and makes each bite tender, even from the same steak.
What to serve with flat iron steak
When you plan how to cook flat iron steak for guests, keep the sides simple so the beef flavour leads. I serve it with beef dripping roast potatoes, a crisp green salad, and peppercorn sauce, or with chips and a fried egg for a quick weeknight supper. For a lighter meal, slice it over rocket with shaved parmesan and lemon dressing.
See also steak cut types, best cut of steak, and steak doneness. Food safety: FoodSafety.gov safe minimum internal temperatures chart.
Recipe card: pan fried flat iron steak
Prep time: 5 minutes, plus 30 minutes to bring the steak to room temperature. Cook time: 6 minutes. Rest time: 5 minutes. Serves: 2.
Ingredients: 400g flat iron steak (feather steak), 1 tablespoon sunflower oil, 25g butter, 1 garlic clove crushed, 1 sprig thyme, flaky sea salt, cracked black pepper.
Method: Pat the steak dry, season with salt and pepper, and let it sit for 30 minutes. Heat a cast iron pan until smoking, add the oil, and sear the steak for 2 to 3 minutes per side. Add the butter, garlic, and thyme, baste for 1 minute, and check the temperature. Rest the steak for 5 minutes, slice thinly against the grain, and serve with the pan juices.
Nutrition per serving (approximate): 420 calories, 38g protein, 1g carbohydrate, 29g fat.
Frequently asked questions about how to cook flat iron steak
Is flat iron steak the same as feather steak?
Yes, they are the same shoulder cut sold under two names in the UK.
How to cook flat iron steak for medium rare?
Cook a 2 cm flat iron steak for 2 to 3 minutes per side in a very hot pan, pull it at 52C, and rest it for 5 minutes. The final temperature after resting reaches about 54C, which is medium rare.
How to cook flat iron steak: do you need to marinate it?
No, because the cut is already tender. A short marinade adds flavour, but salt and pepper alone give an excellent result.
Why is my flat iron steak tough?
Flat iron steak usually turns tough for three reasons: you overcooked it past medium well, you skipped the rest, or you sliced it with the grain instead of against it. Fix all three, and the same steak will taste tender.