In this delicious recipe, Italian-seasoned flank steak is cooked in a cast iron skillet or prepared sous vide, then finished with balsamic roasted cherry tomatoes.
This is one of those recipes I kept meaning to make for months — and now that I finally did, I regret waiting. The combination of Italian-seasoned flank steak and tangy, sweet balsamic-roasted cherry tomatoes is simple, elegant, and full of bright flavor.
Balsamic-roasted cherry tomatoes are a revelation on top of grilled or pan-seared meats, roasted vegetables, polenta, or even crostini. They burst with concentrated flavor and add a glossy, slightly sweet finish that brings the whole dish together. In this post I share two ways to cook the flank steak: a quick oven/cast-iron method and a sous vide technique for perfectly even cooking and unbelievable tenderness.
Ingredients
- 1 flank steak (1½–2 lb)
- 8 tbsp olive oil, divided
- 1 tbsp + 1 tsp Italian seasoning, divided
- ¾ tsp sea salt, divided
- ¾ tsp black pepper, divided
- 8 cloves garlic (4 crushed, 4 whole)
- 2 cups cherry tomatoes
- 2 tbsp balsamic vinegar
- 2 tbsp fresh grated Parmesan cheese, for serving
Method Overview
Choose the oven/cast-iron method for a fast, classic result, or use the sous vide method when you want the steak to be perfectly even and ultra-tender. Both methods finish with roasted cherry tomatoes tossed with balsamic and whole garlic cloves; the tomatoes are roasted while the steak cooks or finishes resting.
Oven / Cast-Iron Skillet Method
- Place the flank steak in a large sealed plastic bag or bowl. Add 4 tbsp olive oil, 1 tbsp Italian seasoning, ½ tsp sea salt, ½ tsp black pepper and the 4 crushed garlic cloves. Toss or massage the steak to coat evenly and let it marinate at room temperature for 10–15 minutes.
- Preheat the oven to 400°F (200°C). Put a cast iron skillet or heavy roasting pan on the upper rack to heat while the oven preheats.
- In a bowl, toss the cherry tomatoes and the 4 whole garlic cloves with the remaining 4 tbsp olive oil, 2 tbsp balsamic vinegar, 1 tsp Italian seasoning, ¼ tsp sea salt and ¼ tsp black pepper. Spread the tomatoes on a baking sheet and place on the lower rack.
- Place the marinated flank steak in the hot cast iron skillet in the oven. Roast 5 minutes on one side, then flip and roast an additional 5 minutes for medium-rare (times will vary slightly by oven and steak thickness).
- Remove the steak and let it rest for 10 minutes before slicing.
- Return the tomatoes to the oven finish (if needed) until they are blistered and slightly collapsed, about 20 minutes total. Serve the roasted cherry tomatoes spooned over the sliced steak and finish with the grated Parmesan.
Sous Vide Method
Sous vide delivers an evenly cooked interior that’s hard to beat. If you don’t have a vacuum sealer, the water displacement method works well with a resealable bag.
- Place the flank steak in a heavy-duty zip-top bag with 4 tbsp olive oil, 1 tbsp Italian seasoning, ½ tsp sea salt, ½ tsp black pepper and the 4 crushed garlic cloves. Toss to coat.
- Fill your sous vide container to the fill line and set the temperature to 131°F (55°C) for medium-rare. Once the water reaches temperature, submerge the bagged steak. Use the water displacement method to remove air if you don’t have a vacuum sealer: lower the bag into the water with the top open until most air is out, then seal.
- Cook the steak for 1–4 hours. The steak will be evenly cooked throughout; longer times will increase tenderness.
- About 20 minutes before the steak finishes, preheat the oven to 400°F and prepare the tomatoes: toss cherry tomatoes and the 4 whole garlic cloves with the remaining 4 tbsp olive oil, 2 tbsp balsamic vinegar, 1 tsp Italian seasoning, ¼ tsp sea salt and ¼ tsp black pepper. Spread on a baking sheet and roast on the lower rack for about 20 minutes until blistered.
- When the sous vide time is up, remove the steak from the bag and pat it dry. Heat a large cast iron skillet or grill pan over high heat and sear the steak about 30 seconds per side to develop a crust.
- Let the steak rest 10 minutes, then slice thinly on a diagonal against the grain. Spoon the roasted cherry tomatoes over the slices and sprinkle with fresh grated Parmesan.
Tips & Variations
- Always slice flank steak against the grain to make each bite tender.
- If you prefer medium, increase oven or sous vide times slightly; use a thermometer to check doneness.
- For extra depth, add a pat of butter to the skillet when searing the steak or finish with a drizzle of aged balsamic vinegar over the tomatoes.
- Serve with creamy polenta, roasted potatoes, or a crisp green salad to complete the meal.
Serving Suggestions
This Italian flank steak with balsamic roasted cherry tomatoes pairs beautifully with creamy cheesy polenta, roasted or grilled vegetables, or a fresh caprese-style salad. Garnish with additional grated Parmesan, chopped fresh basil, or a squeeze of lemon for brightness.
Whether you choose the quick cast-iron route or the precision of sous vide, this recipe yields a flavorful, impressive main course with minimal fuss. The balsamic-roasted tomatoes add a sweet-acid balance that elevates the steak and makes every bite feel special.