Start by measuring the steaks to calculate the exact cooking time. Over time, you'll be able to do this "by eye," but for the first few times, it's a good idea to use a ruler or measuring tape.
Take the steaks out of the fridge and sprinkle them with salt.
Let them sit at room temperature for about 30 minutes.
Pat them dry with a cloth or paper towel, and they are ready for use.
Mix the olive oil with crushed garlic, salt, and pepper.
Toss the langoustine tails in the mixture and let them sit for 5-10 minutes before cooking.
Brush the steaks with olive oil and lightly sprinkle with salt and pepper.
Grill them on a hot grill for the number of minutes that corresponds to the thickness of the steaks.
If your steak is, for example, three centimeters thick, it should cook for three minutes on one side and three minutes on the other side. Set a timer to ring because the time goes by faster than you might think. Do not flip the steaks until they need to be grilled on the other side, and you will get a perfectly grilled steak - every time!
It's important not to flip the steaks before the time is up, or you won't get the delicious, crispy crust that characterizes a good steak.
Place the langoustine tails on the grill the last minute before the meat is done.
Grill the tails until they just change color, and remove them immediately thereafter.
Arrange the langoustine tails on top of the beef steaks and serve, for example, with potatoes and salad.