Pomegranate marinated flank steak is juicy, flavorful, and tender every time. The marinade gives a mouthwatering glossy glaze on the grilled steak. Get all of the tips you need here for excellent flank steak!

​One of the first dinners I remember cooking for friends, with no mom there to supervise or lend a helping hand, was flank steak on the grill. I discovered that, with the proper marinade and timed cooking, I could make this meal perfectly, every time.

Back in the day, despite my lemon-and-garlic upbringing, I went for a commercial Italian dressing marinade for my flank steak recipe. It did taste great with little effort . . . but I just don’t go there these days as I know my pantry is set with pantry ingredients for mouthwatering marinades that are fast and easy to pull together, including incredibly versatile pomegranate molasses that is the star of my pomegranate marinated flank steak recipe.

Best Flank Steak Marinade Ingredients

For the marinade

Pomegranate Molasses. The star player in my pomegranate marinated flank steak is pomegranate molasses. Think of this flavor profile as the Middle Eastern version of a balsamic vinegar: sweet + tart, with an acidic element much like lemon juice, lime juice, or red wine vinegar. But the thick lushness of the pomegranate does so much more than balsamic, giving the steak a gorgeous glossy glaze off the grill, and a steak sauce for dipping.

Dijon mustard. The mustard has its own acidity like the pomegranate molasses, and balances with another layer of umami flavor.

Olive oil. Extra virgin olive oil is my go-to for marinades (and most everything else…). It offers great flavor and nutrition.

Brown sugar. Just a small amount of brown sugar gets us there. The molasses in brown sugar plays so well with the pomegranate molasses, and the boost of sweetness is excellent.

Garlic powder. Look for granulated garlic powder, which offers the best flavor. 

Worcestershire sauce. A dash or two of this seasoning is always great in marinade for great steak.

​Kosher salt and black pepper.

For the steak

1 1/2 pounds flank steak. Flank steak may be known as a tough cut of meat (just ask Dan…he’s a filet mignon guy, but he says he loves my flank steak now too…). What is flank steak called at the grocery store? Often you’ll find it as London Broil. Skirt steak has some similarities in texture but it is a different cut that is longer and thinner. Either steak works here. Hanger steak is not typically substituted for flank steak but it will work well here too, and is a more tender cut of meat.

Vegetables. My recipe is a good marinade for veggies too. Slice up bell peppers and onions to marinate and grill. Your side dish is now done! And so delicious.

How to make Grilled Marinated Flank Steak

Step 1. With a fork, prick the flank steak all over. Season both sides of the steak with the salt and pepper.

Step 2. In a small bowl, whisk the pomegranate molasses, olive oil, mustard, brown sugar, and garlic powder. Set aside about 1/3 of the sauce to use when serving the meat after grilling.

Step 3. Pour the rest of the marinade in a gallon plastic bag, which is the best way to allow the marinade full coverage of the meat (a large bowl also works). Add the flank steak, pepper slices, and onion slices. Pushing out as much air as possible, close the bag and refrigerate the meat for at least 12 hours and up to 24 hours.

Step 4. To grill the meat, use a gas grill or a charcoal grill. Coat the grill grates with neutral oil using tongs and a bit of paper towel. Heat the grill to medium-high heat.

Step 5. Once the grill is hot, lay the flank steak, pepper and onion on the oil-coated grates. Grill for 6- to 8 minutes, then flip the steak and vegetables. Grill for another 6 minutes. Use a meat thermometer (my favorite is the thermo pen instant-read thermometer) to 150 degrees f at the center of the steak.

Step 6. Brush the finished steak with some of the reserved sauce while it rests for 15 minutes. Slice the steak on an angle against the grain, and serve with more of the reserved sauce over top or on the side. Take care not to use the marinade that soaked the raw meat as a dipping sauce unless it is fully heated through and boiled; it is best to use the reserved marinade as the sauce.

How long to marinate flank steak

Flank steak takes a good 12 hours to reach its peak marinated tenderness for juicy flank steak. Marinating is essential for this somewhat tough cut of beef. Up to 24 hours works, but take care not to go beyond that, when the meat fibers begin to break down and we go from juicy steak to  mushy. 

How long to cook flank steak

The key to tender flank steak, in addition to the marinade and marinating time, is cook time. Take care not to overcook the steak! It will be tough if so. Use your timer and thermometer to keep a close eye on everything. Grill one side of the steak for 6 minutes, flip and grill the second side for 6 minutes more, taking the internal temperature to 150°F.

How to slice flank steak

The direction to slice flank steak is key to tenderness with every bite. Lay the grilled flank steak on a cutting board. Keep paper towels handy to soak up any steak juice if needed. Use a long sharp knife such as a chef’s knife to cut thin slices against the grain (across the muscle fibers, not with them).

​What to serve with marinated flank steak

Grilled marinated flank steak is so versatile. On it’s own, sliced, place steak over a bed of Lebanese rice with the grilled marinated vegetables alongside and a great salad such as fattoush salad or tabbouleh salad. Cut into thin strips, it also makes an impressive steak salad, steak fajitas, flank steak tacos. One thing I love about flank steak is that it is excellent at room temperature, so it can be made ahead of time if you like.