Preheat oven to 325F. Pat steaks dry and allow to sit at room temperature 60–90 minutes.

Place peppercorns in a heavy-duty resealable bag and set on a Sheet Pan. Using a heavy Saucepan, crack peppercorns so they are broken but still coarse in texture, then pour onto Sheet Pan.

Season steaks on both sides with 1 ½ teaspoons salt.

Push one side of each steak into the cracked peppercorns to coat.

Heat a large Enameled Cast Iron Skillet over medium-high heat. Add oil and heat until shimmering.

Working in batches if necessary, sear sides of steak to render fat, about 2 minutes.

Sear pepper side down, 1 ½–2 minutes to develop a brown crust. Flip pepper side up, add butter to Skillet, and baste steaks, 1–2 minutes more.

Remove steaks from Skillet (reserve Skillet for pan sauce) and transfer to a Cooling Rack set over a Sheet Pan. Bake until they reach an internal temperature of 130F for medium rare, 6–8 minutes depending on thickness of steak.

While steaks bake, assemble the pan sauce: return Skillet (no need to wipe out) to medium heat, add shallots and remaining ½ teaspoon salt and saute 1 minute.

Stir in green peppercorns, then chipotles, then mezcal. Flambé if comfortable, or reduce the liquid until all the alcohol has cooked off, about 1 minute.

Stir in beef broth and heavy cream and bring to a boil.

Rapidly simmer until the sauce has reduced by half, 8—10 minutes. The sauce should be a “nappe” consistency, or thick enough to coat the back of a spoon.

Allow steaks to rest for 5 minutes before serving.

Add any steak drippings from the Sheet Pan to the sauce, stir to incorporate.

Spread sauce on the bottom of a Serving Platter. Slice steak and fan on top of sauce. Top with parsley and flaky salt, if using.