Mastering the Grill: The Ultimate Soy, Ketchup, and Sesame Flank Steak Marinade Recipe

There’s something uniquely satisfying about cooking on the grill. The sizzle of meat hitting hot grates, the smoky aroma wafting through the air, and the anticipation of a perfectly charred, tender meal – it’s an experience that brings people together and elevates even the simplest ingredients. With more of us embracing outdoor cooking, I’m thrilled to share a truly delicious marinade recipe that my sister-in-law, Jamie, recently passed along to me. This isn’t just any marinade; it’s a game-changer for anyone looking to infuse incredible flavor and tenderness into their grilled meats, especially cuts like flank steak or London broil.

I recently used this marinade with a beautiful flank steak, and while I might have left it on the grill a tad longer than my ideal ‘medium-rare’ (a little more pink would have been perfect!), the flavor profile was absolutely outstanding. The beauty of this recipe lies in its simplicity and versatility. It’s perfect for those busy weeknights when you need an easy yet impressive dinner, provided you remember the crucial step: marinating the steak that morning or the day before. Trust me, the minimal effort for this preparation yields maximum flavor rewards.

A huge thank you to Jamie for sharing this culinary gem! It has quickly become a staple in my grilling repertoire.

The Magic of Marinades: Elevating Your Grilling Game

Before diving into the recipe, let’s talk about why marinades are so essential, especially for tougher cuts of meat. A good marinade serves several crucial purposes: it tenderizes, it infuses flavor, and it can even create a beautiful crust during cooking. The acidic components (like ketchup in this case, or vinegar/citrus in others) help to break down the surface proteins of the meat, making it more tender. The oil helps to retain moisture and transfer fat-soluble flavors, while the salt (from soy sauce) helps the meat retain moisture and enhances taste. The aromatics and spices complete the flavor profile, ensuring every bite is bursting with taste.

For cuts like flank steak, which are lean and can be tough if not cooked correctly, marinating is not just an option but a necessity for optimal tenderness and flavor. This recipe strikes a perfect balance, offering a savory, slightly sweet, and aromatic blend that penetrates deep into the meat fibers.

Soy, Ketchup, and Sesame Marinade: A Flavorful Symphony

The combination of ingredients in this marinade might seem unconventional at first glance, but they come together to create a remarkably harmonious and addictive flavor. Each component plays a vital role:

3/4 cup low-sodium soy sauce: This forms the savory backbone of the marinade. Soy sauce brings a deep umami flavor and a crucial salty element that seasons the meat from within. Opting for low-sodium is important here, as it allows you to control the overall saltiness and prevents the marinade from becoming overpowering. Beyond flavor, the enzymes in soy sauce can also contribute to the tenderizing process.
1/4 cup ketchup: Don’t underestimate the power of ketchup in a savory marinade! It provides a delightful balance of sweetness, acidity, and a subtle tang from the tomatoes and vinegar. This sweetness helps with caramelization on the grill, resulting in a beautiful, slightly charred exterior. It also adds a nice body and viscosity to the marinade.
1/4 cup chopped scallions: Scallions, also known as green onions, offer a fresh, mild oniony flavor without the pungency of raw onions. They add a vibrant, aromatic quality that brightens the overall profile of the marinade. The fresh green tops also contribute a subtle herbaceous note.
1 1/2 TBLS sesame oil: A little goes a long way with sesame oil, especially the toasted variety. It delivers a rich, nutty, and distinctly Asian-inspired aroma and flavor that ties all the ingredients together. Sesame oil adds a layer of complexity and depth that makes this marinade truly special and unique.

The Marinade Process: Simple Steps for Maximum Flavor

Creating this marinade is incredibly straightforward, which is part of its appeal for busy schedules.

Ingredients:
Soy, Ketchup, and Sesame Marinade
3/4 cup low-sodium soy sauce
1/4 cup ketchup
1/4 cup chopped scallions
1 1/2 TBLS sesame oil

Instructions:

Combine all ingredients in a large zip-top plastic bag. This method is highly recommended for marinading as it allows for maximum surface contact with the meat while using less marinade, and cleanup is a breeze. Ensure the bag is sealed tightly and gently massage it to mix the ingredients thoroughly.
Add 1 lb (or larger) flank steak to the bag. Make sure the steak is fully submerged and coated by the marinade. If using a larger piece of meat, you might want to slightly increase the marinade quantity to ensure complete coverage.
Refrigerate for at least 4 hours or overnight. This step is critical. Four hours will infuse a good amount of flavor, but for optimal tenderness and a more profound taste, marinating overnight (8-12 hours) is highly recommended. Avoid marinating for longer than 24 hours, as the acids in the marinade can start to break down the meat too much, leading to a mushy texture.
When ready to grill, remove steak from bag. Lift the steak out, allowing any excess marinade to drip back into the bag.
Discard marinade. For food safety reasons, never reuse a marinade that has been in contact with raw meat. The bacteria from the raw meat can contaminate any food it touches. If you wish to have a sauce, reserve a small portion of the marinade *before* adding the raw meat, or better yet, make a separate fresh batch for serving.

Grilling Your Flank Steak to Perfection

Cooking flank steak on the grill is an art, but with a few simple tips, you can achieve fantastic results every time. Flank steak is best cooked quickly over high heat to a medium-rare or medium doneness. Overcooking will render it tough and dry.

Grilling Steps:

Preheat your grill: Get your grill (gas or charcoal) to a high heat, aiming for about 450-500°F (230-260°C). A hot grill is essential for a good sear and to prevent the meat from sticking. Clean the grates thoroughly with a wire brush once hot, then lightly oil them.
Grill the steak: Place the marinated flank steak directly over the high heat. Grill for approximately 6 minutes on each side, or until your desired degree of doneness. For medium-rare (which is ideal for flank steak), aim for an internal temperature of 130-135°F (54-57°C). Use a meat thermometer for accuracy. Remember, cooking times can vary based on the thickness of your steak and the actual temperature of your grill. You’re looking for a beautiful crust on the outside and a juicy interior.
Rest the meat: This is a step often overlooked but incredibly important. Once the steak reaches your desired doneness, remove it from the grill and place it on a cutting board. Tent it loosely with foil and let it rest for at least 5-10 minutes. Resting allows the juices within the meat to redistribute, resulting in a more tender and flavorful steak. If you cut into it too soon, all those delicious juices will simply run out onto your board.
Slice diagonally across the grain: Flank steak has very distinct muscle fibers, or “grain.” To ensure maximum tenderness, it is crucial to slice the cooked steak against these fibers. Identify the direction of the grain, then cut diagonally across it into 1/4 to 1/2 inch slices. This shortens the muscle fibers, making each bite much easier to chew and more enjoyable.

Serving Suggestions and Variations

This marinated flank steak is incredibly versatile and pairs well with a variety of sides, making it a perfect centerpiece for a weeknight meal or a casual gathering.

What to Serve With It:

Rice: Steamed white or brown rice is a classic accompaniment, perfect for soaking up any remaining juices.
Roasted or Grilled Vegetables: Asparagus, broccoli, bell peppers, or corn on the cob would complement the flavors beautifully.
Salad: A simple green salad with a light vinaigrette or an Asian-inspired slaw would offer a refreshing contrast.
Noodles: Consider serving it alongside a quick stir-fry noodle dish.
Potatoes: Mashed potatoes, roasted potatoes, or even sweet potato fries can be a hearty side.

Marinade Variations:

While the original recipe is fantastic, you can easily adapt it to your taste or experiment with other proteins:

Add Aromatics: For an extra flavor boost, finely mince 1-2 cloves of garlic and about 1 tablespoon of fresh ginger and add them to the marinade.
A Touch of Heat: If you enjoy a bit of spice, a pinch of red pepper flakes or a dash of sriracha can be added to the mixture.
Citrus Kick: A squeeze of fresh lime or orange juice can brighten the flavors and add another layer of acidity for tenderization.
Other Proteins: This marinade isn’t just for flank steak! It would be equally delicious on chicken thighs, pork tenderloin, or even sturdy fish like salmon. Adjust marinating times accordingly (chicken/pork 2-6 hours, fish 30-60 minutes).

Food Safety First: Important Reminders

Whenever you’re working with raw meat and marinades, food safety is paramount. Always:

Refrigerate During Marinating: Never marinate meat at room temperature. The refrigerator keeps the meat at a safe temperature to prevent bacterial growth.
Discard Used Marinade: As mentioned, always discard any marinade that has come into contact with raw meat. If you want to use some as a sauce, either set aside a portion before adding the meat or boil the used marinade for at least 5 minutes to kill any bacteria, though making a fresh batch is generally safer and recommended.
Prevent Cross-Contamination: Use separate cutting boards, utensils, and plates for raw meat and cooked meat. Wash your hands thoroughly with soap and warm water after handling raw meat.

This Soy, Ketchup, and Sesame Marinade recipe, generously shared by Jamie, is truly a culinary gift. It’s incredibly easy to prepare, uses readily available ingredients, and consistently delivers a deeply flavorful and tender grilled steak. Whether you’re a seasoned grill master or just starting your outdoor cooking journey, this recipe is guaranteed to impress. So fire up your grill, prepare this fantastic marinade, and get ready to enjoy a mouth-watering meal that will leave everyone asking for the recipe. Happy grilling!