1. In a bowl, whisk together the balsamic vinegar, olive oil, Dijon mustard, minced garlic, Worcestershire sauce, brown sugar, salt and black pepper until well combined.

2. Place the flank steak in a shallow dish or resealable bag. Pour the marinade over the steak and turn it several times to coat well. Cover and refrigerate for at least 1 hour, or up to 8 hours for deeper flavour.

3. While the steak marinates, combine the crumbled blue cheese, panko breadcrumbs, Parmesan, chopped parsley, olive oil and black pepper in a bowl. Mix gently until the ingredients form a crumbly, evenly combined mixture.

4. Remove the steak from the marinade and pat it lightly dry. Heat a large oven-safe skillet or grill pan over medium-high heat. Sear the steak for 3–5 minutes per side, depending on its thickness and desired level of doneness.

5. Press the blue cheese mixture evenly over the top of the seared steak, creating a generous crust across the surface.

6. Transfer the skillet to a preheated grill or broiler. Cook for 2–3 minutes, until the blue cheese topping is melted and golden.

7. Transfer the steak to a cutting board and allow it to rest for 5–10 minutes. This gives the juices time to redistribute before slicing.

8. Slice the flank steak thinly against the grain. Arrange the slices over rocket or mixed greens and garnish with fresh parsley. Drizzle with a little extra balsamic glaze if desired and serve immediately.