Beef steak with spicy pesto sauce

Ingredients:

• 1 piece (weighing 1 kg) of thick beef fillet (round loin), boneless (3 cm thick)
• 1/2 cup olive oil
• Juice of 1 lemon
• Coarse salt and freshly ground pepper
• 1/4 cup pine nuts
• 1 bunch of parsley (leaves only)
• 1 clove of garlic
• 1/2 tsp red pepper flakes
• 1/4 cup finely grated Parmesan or grana padano cheese
• 1/4 cup chopped pitted green olives

Preparation:

1. Using a meat tenderizer, pierce the meat all over or with a fork. Place in a large zip-top bag; add 2 tablespoons olive oil, lemon juice, 1/2 teaspoon salt, and a pinch of ground pepper. Seal the bag and spread the marinade evenly over the meat; marinate in the refrigerator for 2 to 8 hours.
2. Meanwhile, prepare the pesto sauce: Toast the pine nuts in a skillet over medium-high heat, shaking the pan occasionally, until golden brown, about 3 minutes; cool. Process the parsley, garlic, and pepper flakes until almost uniform consistency.
   
   Add toasted pine nuts, cheese, and 5 tablespoons of olive oil and mix until smooth. Transfer the sauce to a bowl and stir in 3 tablespoons of water and olives; season with salt.
3. Remove the meat from the marinade and pat dry. Bring to room temperature, about 30 minutes.
4. Heat a large cast-iron skillet or any heavy skillet to medium-high heat; add the remaining 1 tablespoon olive oil, then place the steak in the skillet and cook until darkened, about 7 minutes.
   
   Flip the meat over and continue cooking for approximately 8 more minutes. Check for doneness by inserting a thermometer into the side of the steak; for medium-rare, the thermometer should read 131°F (55°C). Place the steak on a cutting board and let it rest for 10 minutes.
5. Brush the steak with a little pesto sauce. Then slice thinly across the grain and serve with the remaining pesto sauce.