Classic Recipe: Steak au Poivre With Roast Potatoes

“IT’S THE HEIGHT of French cuisine,” said Lee Hanson of this steak au poivre, the sort of classic, crowd-pleasing fare he and co-chef Riad Nasr will offer at their all-day brasserie, Frenchette, opening in a few weeks in Manhattan’s Tribeca.

Peppercorn-crusted filet mignon in a cream sauce comes with a side of buttery roast potatoes. Flambéing the shallots imparts caramelized flavor to the quick pan sauce—easy to pull off, as long as you’re careful. But if you want to skip the flambé, the dish will still be delicious. “You...