Preheat the grill or grill pan - Preheat the grill or grill pan over high heat. Meanwhile, prepare the marinade for the steak. - If using an outdoor grill, make sure to brush the grates well with oil to prevent the steak from sticking. A well-oiled grill will also help achieve the perfect grill marks.

Marinate the steak - In a bowl, mix 1 tablespoon of olive oil with 1/2 teaspoon of salt and 1/4 teaspoon of black pepper. Add the steak slices and toss to coat well. Let sit at room temperature for 10 minutes. - Make sure to slice the steak against the grain to obtain tender and juicy slices.

Prepare the crostini - Slice the baguette diagonally into 1/2 inch thick slices. Brush each slice with olive oil on both sides and sprinkle lightly with salt. Grill the slices for 2-3 minutes per side or until golden brown and crispy. Rub the garlic clove over each slice while they are still warm. - If you prefer, you can also toast the bread slices in the oven or in a toaster. Make sure to adjust the cooking time accordingly.

Grill the steak - Grill the steak slices for 2-3 minutes per side for medium-rare doneness. Remove from the grill and let rest for 5 minutes. - Do not overcrowd the grill pan or the outdoor grill, as this will cause the steak to steam rather than sear. Overcooked steak will be tough and chewy, so make sure to keep a close eye on it.

Assemble the crostini - Top each crostini slice with a few arugula leaves, followed by a few strips of steak and crumbled gorgonzola cheese. Serve immediately. - If you prefer, you can also add a drizzle of balsamic glaze or honey to the crostini for extra flavor. Just make sure not to overload the toppings, as the bread slices might get soggy.