Grilled Flank Steak
I have made Flank Steak hundreds of times, and in this post I will show you how to make the most perfectly cooked, best Grilled Flank Steak. Use this grilling method to cook any piece of flank, whether you’re cooking with salt only or using the balsamic rosemary marinade that I share below.
Beef is hands down my favorite meat, and over my many years of cooking and eating, I have loved becoming familiar with each and every cut.
While Ribeye and Prime Rib tend to get the most attention, I think flank steak is an incredible cut. It is full of flavor and remarkably tender, so long as it’s cooked right. Simply sliced against the grain and served, it makes for a very satisfying main course.
Should You Marinate or Not?
By no means is it necessary to marinate flank steak. Most of the time I prepare this cut, I simply sprinkle it with salt and throw it on the grill. It’s plenty tender without marinade, and I love getting to appreciate the flavor.
However, when I have company over, I do like to prepare some sort of flank steak marinade. The rosemary balsamic marinade I share here is my favorite, but you can also try Chimichurri.
Ingredients You’ll Need
If you wish to simply grill flank steak with salt, then follow the instructions below without the marinade. However, for extra flavor, we will use extra virgin olive oil, balsamic vinegar, Dijon mustard, fresh garlic, fresh rosemary, salt, and black pepper:
Tips for Best Results
Choose a good piece of beef – Flank by nature is very lean, and because of that, I recommend choosing conventional over grass fed beef. Also ask the butcher for the most evenly thick piece of meat, so it cooks more consistently.
Do not rest the beef at room temperature before cooking – One of the biggest secrets to a great Grilled Ribeye or steak is to rest it at room temperature at least an hour ahead of time. However, because flank is so thin, here I actually do not recommend it. A colder piece of meat to start will allow us to caramelize the outside more thoroughly on the grill without overcooking the interior.
Don’t marinate too little or too long – Flank is plenty tender without marinade. The marinade here is more for flavor, so you’ll want to marinate the meat for at least 4 hours for good results. However, do not marinade for longer than one day, or the beef will taste too acidic from the balsamic.
I’m going to share step-by-step photos of exactly how I grill this piece of beef, and if you follow it, you will have a gorgeously caramelized exterior and a wonderfully pink interior, like this:
Make the Marinade
In a ziptop plastic bag, combine extra virgin olive oil, balsamic vinegar, Dijon mustard, chopped rosemary, pressed or minced fresh garlic, salt, and pepper:
The plastic bag allows us to use and waste less marinade, and properly coat the beef in flavor.
Swish the marinade around to combine it, then inspect your piece of beef. The end on the right gets a little bit thin, but I prefer not to trim it and just have a “crispy bit” on the edge that I know will get slightly overcooked. However, feel free to trim the meat if you prefer.
Place the flank in the marinade bag, and squeeze out as much air as possible.
Then marinate for at least 4 hours, and up to 1 day ahead of time.
Time to Cook!
Heat a gas grill on high for at least 10 minutes, making sure to heat ALL burners, because we will be shifting the meat around to maximize caramelization.
If you have a temperature gauge on your grill, it should be 600 to 700F when properly preheated. Cooking flank steak properly is all about super hot and fast heat.
Take the beef out of the marinade, then lay it on the center of the grill, making sure to leave the burners going on the left and right sides:
Close the lid and cook for 90 seconds, then open the lid and check that the underside has caramelized nicely:
Pivot the beef 90 degrees and over to the left side of the grill, then close the lid and cook for another 90 seconds.
Open the lid, and check that you have some nice grill marks and caramelization going the other way:
Now flip the meat over all the way to the right side of the grill, which should be screaming hot from preheating all this time:
Close the lid and cook for 90 seconds, then check for grill marks:
Finally, pivot the beef back to the center burner (which should have been going this whole time) and close the lid for another 90 seconds.
Because flank is so thin, it’s time to check for doneness.
Check the Temperature
The perfect flank steak temperature for me is to pull the beef off the grill somewhere between 125F and 130F. Carryover cooking as the meat rests will increase the temperature about 5 degrees, so always keep that in mind.
Temperatures for Doneness:
I love to enjoy flank at medium rare, but here are guidelines for other levels of doneness:
- Rare – 125°, very red inside, cool interior
- Medium rare – 135°, red inside and warm
- Medium – 145°, pink inside and warm
- Medium well – 150°, slightly pink inside and warm
- Well – 160°, no pink inside
Rest the Beef Before Slicing
Always let the meat rest on a wire rack, plate, or tray for at least 5 minutes. If you cut into the beef right away, all the tasty juices will run out onto your plate. Resting gives the juices time to redistribute and stay in the meat when you slice it.
What to Serve with this Recipe
This Balsamic Marinated Flank Steak is an incredibly versatile main dish, with many pairing options.
What to Do with Leftovers
In general, beef does not reheat well, and it’s always far superior when it’s cooked fresh. For this reason, I prefer to use the flank steak leftovers in cold settings, like for this delicious Steak Salad with queso fresco, cherry tomatoes, avocado, and cilantro lime dressing. If you prefer to reheat the beef, see the instructions below.
Place in an airtight container in the fridge for up to 5 days.
Place in a 250F oven for about 10 minutes, until the beef feels warm to the touch. You may also try the microwave, but use 50% power and check the beef frequently, as it will very quickly overcook and lose its pink and tender interior.
Yes, beef freezes very well. Store in an airtight container for up to 2 months.
Balsamic Marinated Grilled Flank Steak
- 1/2 cup extra virgin olive oil
- 1/4 cup balsamic vinegar*
- 2 tbsp Dijon mustard
- 2 tbsp finely chopped rosemary leaves
- 4 large garlic cloves pressed or minced
- 2 tsp kosher salt
- ½ tsp freshly ground black pepper
- 2 lbs flank steak**
- Combine everything except the flank steak (the olive oil, balsamic vinegar, Dijon mustard, rosemary, garlic, salt, and black pepper) in a gallon-sized ziptop plastic bag. Shake or swish the bag to combine.
- Place the flank steak in the bag of marinade and squeeze out as much air as possible before closing the bag tightly. Squeezing out the air ensures that the flank steak is sufficiently coated in the marinade.
- Marinate the flank ideally for 4 hours*** and up to 1 day ahead.
- Preheat a gas grill on high for at least 10 minutes, heating all burners.
- Remove the meat from the marinade, then place in the center of the grill. Close the lid, and cook for 90 seconds.
- Check that there are grill marks underneath, then pivot the meat 90 degrees over to the left part of the grill, and again close the lid and cook for 90 more seconds.
- Check that there are grill marks underneath, then flip the steak over all the way to the right part of the grill. Close the lid, and cook for 90 seconds.
- Pivot the meat 90 degrees back to the center of the grill, close the lid, and cook for another 90 seconds.
- Because flank is so thin, there's a good chance it's already done. Check internal temperature with a thermometer. I aim for between 125F and 130F, but you may cook to your desired level of doneness, repeating these 90 second intervals with the lid closed. Just remember that the meat will rise another 5 degrees while resting because of carryover cooking.
- Remove the flank to a wire rack or tray and let rest for at least 5 minutes before slicing and serving. Enjoy!
Nutrition is estimated using a food database and is only intended to be used as a guideline for informational purposes.