One of my favorite new grilling recipes is this balsamic flank steak, served over charred zucchini with creamy whipped feta and finished with a sweet, tangy balsamic glaze. It’s a complete meal that comes together quickly—about 30 minutes of active cooking—and packs a lot of flavor.
The steak develops a crisp, caramelized exterior while remaining juicy and tender inside. A simple marinade infuses the meat with savory, tangy notes, and the glaze—reduced from the reserved marinade—adds a glossy, concentrated finish. Paired with grilled zucchini and a smooth whipped feta, the dish feels elevated but is straightforward to make at home.
Why You’ll Love This Balsamic Flank Steak
- Restaurant-quality flavor with minimal effort.
- Packed with protein and bold, balanced flavors.
- Contrasting textures—charred zucchini, creamy feta, and tender steak.
- Uses a relatively lean cut that grills quickly.
- Pairs beautifully with red wine or a bright, refreshing salad.
- Ready to serve in under 30 minutes of active cooking time.
Ingredients You Need
Below are the ingredients used to make this balsamic marinated flank steak. Adjust quantities as needed for serving size.
- Flank steak: a flat, grainy cut that’s flavorful and relatively lean—best when marinated and grilled quickly over high heat.
- Dijon mustard: adds mild heat and depth.
- Garlic: fresh minced garlic brightens the marinade.
- Onion powder: enhances savory notes.
- Soy sauce: provides umami; use coconut aminos for a gluten-free alternative.
- Olive oil: or avocado oil to help the marinade cling and promote searing.
- Balsamic vinegar: the star ingredient—add more if you prefer a tangier finish.
- Black pepper and salt: to taste.
- Zucchini: sliced lengthwise, brushed with oil, and grilled until charred.
- Feta cheese: use the block in brine and blend with cream or milk for a whipped, spreadable texture.
- Heavy cream or milk: to smooth the whipped feta.
Substitutes for Flank Steak
Flank steak is lean and benefits from a marinade and a quick, high-heat cooking method. If you prefer a similar alternative for grilling, consider skirt steak, which responds well to marinades and shares a comparable texture and flavor profile.
How to Make Balsamic Flank Steak
The following summarizes the steps. See the recipe card below for exact measurements and a printable version.
Step 1. Marinate. Whisk together Dijon, garlic, onion powder, soy sauce, olive oil, and balsamic vinegar in a large plastic bag or shallow dish. Season the steak with salt and pepper, add it to the marinade, and refrigerate for at least 2 hours or overnight for best flavor.
Step 2. Grill the steak. Preheat the grill to high (about 450°F). Remove the steak from the marinade, shake off excess (reserve the marinade for the glaze), and place the steak on the hot grates. Grill 3–5 minutes per side for medium-rare, or until the internal temperature reaches roughly 135°F before resting.
Step 3. Grill the zucchini. Brush zucchini slices with a little olive oil and salt. Add them to the grill when you flip the steak and cook 2–3 minutes per side until tender with charred spots. Press gently with tongs for clear grill marks.
Step 4. Rest and slice. Transfer steak and zucchini to a clean cutting board and let rest for 10 minutes. Resting allows juices to redistribute and carryover cooking to finish.
Step 5. Make the glaze. Bring the reserved marinade to a rolling boil in a saucepan to ensure food safety, then reduce heat and simmer until it thickens to a glaze consistency, about 2–3 minutes. The glaze should coat the back of a spoon.
Step 6. Whip the feta and serve. Blend the feta and cream or milk until smooth. Brush half the glaze over the steak, slice thinly against the grain, and plate over whipped feta with grilled zucchini. Drizzle with remaining glaze and garnish with fresh herbs if desired.
Best Temperature to Grill Steak
Flank steak responds best to high heat and a quick cook, so preheat the grill to around 450°F for a good sear. Use an instant-read thermometer to check doneness: remove the steak at about 135°F for medium-rare, then let it rest to reach final temperature.
How to Cut Flank Steak
Always slice flank steak thinly against the grain. Cutting across the grain shortens muscle fibers and gives you tender bites. Use a sharp knife and steady strokes for clean slices.
More Expert Tips for Grilling Steak
- Marinate the steak in the refrigerator and turn it occasionally so the marinade coats the meat evenly.
- Pat the steak surface and grill grates as dry as possible before cooking for better searing.
- Reserve some marinade to boil into a glaze; always bring used marinade to a vigorous boil to ensure safety.
- Preheat the grill thoroughly to achieve a strong sear that locks in juices.
- Limit flipping the steak—let it form a crust before turning.
- Use a meat thermometer for reliable results and let the steak rest 5–15 minutes before slicing.
Can I Make This in the Oven?
If you don’t have a grill, sear the steaks in a hot cast-iron skillet and finish under the broiler for 4–6 minutes per side, depending on thickness. Roast zucchini on a baking sheet at 400°F for 12–15 minutes, then broil briefly to add char.
How to Store
Keep leftovers in an airtight container in the refrigerator for 3–4 days. Reheat gently on the stove or in a covered skillet to preserve texture.
More Delicious Flank Steak Ideas
If you enjoy flank steak, try variations like stuffed flank steak, a vegetable-packed stir-fry, or a one-pan garlic herb steak and potatoes for different weeknight or weekend meals.
Balsamic Flank Steak
A quick marinated and grilled flank steak finished with a reduced balsamic glaze, served over grilled zucchini and a whipped feta spread.
Ingredients
Balsamic Flank Steak
- 1.5 lb flank steak
- 2 tsp Dijon mustard
- 4 cloves minced garlic
- 2 tsp onion powder
- 3 Tbsp soy sauce or coconut aminos
- 3 Tbsp olive oil
- 1/2 cup balsamic vinegar (plus more if desired)
- Salt and black pepper to taste
Zucchini and Whipped Feta (Optional)
- 3 large zucchini, ends trimmed and sliced lengthwise
- 2–3 Tbsp olive oil
- Kosher salt to taste
- 8 oz feta cheese, in the brine
- 3 Tbsp heavy cream or milk
Instructions
- Combine Dijon, garlic, onion powder, soy sauce, olive oil, and balsamic vinegar in a large plastic bag or shallow dish. Season the steak with salt and pepper, add it to the marinade, and refrigerate for at least 2 hours or overnight.
- When ready to cook, preheat the grill to high (about 450°F). Remove the steak from the marinade, shake off excess, and reserve the remaining liquid for the glaze. Grill the steak 3–5 minutes per side for medium-rare, or until the internal temperature reaches about 135°F before resting.
- Brush the zucchini with a little oil and season with salt. Add zucchini to the grill when you flip the steak and cook 2–3 minutes per side until tender and charred. Press with tongs to enhance grill marks.
- Transfer the steak and zucchini to a cutting board and let rest for 10 minutes.
- While resting, bring the reserved marinade to a rolling boil in a small saucepan (to ensure safety), then reduce to a simmer and cook 2–3 minutes until thickened into a glaze. Add a splash more balsamic if desired.
- Blend the feta and heavy cream or milk until smooth to make the whipped feta.
- Brush half the glaze over the steak, slice thinly against the grain, and plate over the whipped feta with zucchini. Drizzle with remaining glaze and serve.
Notes
This recipe highlights the balance of tangy balsamic with savory, umami-rich marinade components. Boiling the reserved marinade before using it as a glaze ensures it is safe to serve.
Nutrition (per serving)
Calories: 553 kcal | Carbs: 12 g | Protein: 41 g | Fat: 38 g | Sodium: 1117 mg. Nutrition values are approximate and provided for guidance.
I adapted and developed this version after seeing a similar steak-and-zucchini dish. If you try it, slice against the grain and enjoy the contrast of the tangy glaze against the creamy feta and smoky zucchini.