- In a bowl, combine olive oil, hot pepper flakes, rosemary, oregano, and garlic.
- Arrange flap steaks on a dish and rub both sides with marinade.
- Cover with plastic wrap and let marinate for 24 hours in fridge. Remove meat from fridge 1 hour before cooking and let stand at room temperature.
- Preheat barbecue to high and oil grill. Barbecue flap steaks about 5 minutes per side, until internal temperature reaches 63°C (145°F) for rare doneness or continue cooking until internal temperature reaches 70°C (160°F) for medium doneness.
- Let stand 5 minutes in a dish. In the meantime, drizzle mache with olive oil and white balsamic vinegar.Season with salt to taste and toss to combine.
- Slice meat about 1.5 cm (¾ in.) thick and arrange on a serving dish.
- Cover with mache salad, toasted almonds and a few Parmesan flakes. Drizzle with olive oil and serve.
Flap steak is at its most tender when served rare.
To toast almonds, spread a single layer on a baking sheet and toast in the oven at 180°C (350°F) for 7 to 10 minutes, or until they start to turn golden.