Remove the lamb chops from the refrigerator 20-30 minutes before searing to allow them to come to room temperature. Pat them dry with a paper towel and season generously with salt.
Combine the pink, black, and white peppercorns in a mortar and pestle and crush into a fine powder.
Press the crushed pepper firmly onto both sides of the lamb.
Let chops sit at room temperature for 20–30 minutes.
Heat a cast iron skillet over medium-high heat.
Add the olive oil. When shimmering, add the lamb chops.
Sear until deeply browned, about 3-5 minutes per side. Aim for around 130–135°F for medium rare or 140–145°F.
Remove lamb to a plate and rest.
Lower heat to medium. Discard excess fat, leaving about 1 tbsp in the pan.
Add shallots (and garlic, if using) and cook 30–60 seconds until softened.
Add the brandy, scraping up any browned bits on the bottom of the pan and reincorporating into the liquid.
Add stock and cream, simmering until slightly thickened, 3–5 minutes.
Spoon sauce over lamb chops or serve alongside. Enjoy!