1. Take the meat out of the refrigerator 10 minutes in advance.
Brush both sides with oil using a brush to prevent it from sticking to the pan.
Season your steak with salt to enhance its flavor and preserve its juices, then pepper it.
2. Meanwhile, clean the lettuce and tomatoes.
Cut the leaves and tomatoes. Arrange in a salad bowl.
3. Prepare the vinaigrette: Mix olive oil and balsamic vinegar. Add mustard, a pinch of salt and pepper, and mix.
4. Slice the shallot and add it to the vinaigrette. Season with salt and pepper. Set aside.
5. Heat your pan (grill) well and place the meat in it.
Cook your steak for 4 minutes on one side without touching it.
6. Flip it over and cook for another 4 minutes, still without touching it.
7. Gently press the steak to check its doneness. A medium-rare steak should remain tender.
8. After cooking, let your steak rest for a few minutes on a preheated plate for even distribution of the meat's juices.
9. Pour the vinaigrette over your salad.
Serve your steak with the crisp salad and delicious fries.