Chicken au Poivre

Steps

1. Remove the tenderloin from the underside of each chicken breast and save it for another use. Place the breasts one at a time in a zip-top bag and pound the thick end with a rolling pin or the bottom of a heavy pan to an even 1/2 inch (1.5 cm). Pat them very dry with paper towels.
2. Coarsely crack the peppercorns in a mortar or by crushing them under a heavy skillet. Shake them in a fine-mesh sieve to remove the powder. Salt the breasts on both sides, then press the cracked pepper firmly onto both sides so it sticks.
3. In a large stainless steel or cast-iron skillet, heat the oil and 2 teaspoons (10 g) of butter over medium-high heat. When the butter foams and the foam starts to subside, add the chicken and leave it untouched for 4 to 5 minutes, until a deep golden crust forms.
4. Flip, lower the heat to medium, and cook 3 to 5 minutes more, until the thickest part reaches 165°F (74°C). Transfer to a plate and tent loosely with foil.
5. Lower the heat to medium-low. If there is a lot of fat in the pan, pour off all but a spoonful. Add another 2 teaspoons (10 g) of butter and the finely minced shallots, and cook for 2 minutes, scraping up the browned bits with a wooden spoon, until translucent.
6. Take the pan off the heat and pour in the cognac. To flambé, turn off the range hood, return the pan to the heat, and bring a long lighter to the edge of the pan: let the flames die out on their own, about 30 seconds. If you are not flambéing, simply let the cognac reduce for 1 minute over medium heat until almost dry.
7. Pour in the chicken broth and reduce by half over high heat, 3 to 4 minutes.
8. Add the cream, the mustard, and any juices from the resting chicken. Simmer over medium heat for 3 to 4 minutes, until the sauce coats the back of a spoon and a finger swiped through it leaves a clean line. Taste and add salt if needed.
9. Off the heat, swirl in the remaining 2 teaspoons (10 g) of cold butter for a glossy sauce. Return the chicken to the pan for 1 minute, turning it to coat and warm through, without letting the sauce boil.
10. Plate the chicken on warm plates, spoon the sauce over it, and scatter with chopped flat-leaf parsley. Serve right away.