Beefsteak With Potatoes

8 slices fillet of beef, 2.5 cm thick
10 cl olive oil
2 tablespoons chopped parsley
2 tablespoons chopped onion
1 tablespoon lemon juice

Using a mallet, flatten each slice of beef to a thickness of about 1 cm. Marinate the slices in a mixture of spices, olive oil, parsley, onion, and lemon juice. Grill the meat on each side at a very high heat for a few moments. It is essential to serve the slices rare and very hot. Serve with potatoes cooked in butter and flavored with fines herbes.