FOR THE SAUCE:

Melt 1 tablespoon butter in 12-inch skillet over medium heat; add shallot and cook, stirring occasionally, until softened, about 2 minutes. Add beef and chicken broths; increase heat to high and boil until reduced to about 2 cup, about 8 minutes. Set aside.

FOR THE STEAKS:

Meanwhile, pat steaks dry with paper towels and sprinkle both sides of steaks with salt; rub 1 side of each steak with crushed peppercorns and, using your fingers, press peppercorns into steaks to adhere.

Heat oil in clean, dry skillet over medium heat until hot, about 4 minutes. Place steaks, unpeppered side down, in hot skillet; increase heat to medium-high. Firmly press on steaks with bottom of another pan or a flat pot lid; remove cake pan; and cook steaks, without moving them, until well browned, about 6 minutes. Using tongs, flip steaks, press down on steaks with bottom of pan or flat pot lid; remove pan and cook on peppered side until meat registers 115–120° (for rare), 120–125° (for medium-rare), or 130–135° (for medium), about 3 to 5 minutes. Transfer steaks to large plate and tent with aluminum foil.

Pour 4 tablespoons brandy, cream, and reduced broth mixture into now-empty skillet; increase heat to high and bring to boil, scraping up any browned bits. Simmer until deep golden brown and thick enough to heavily coat back of metal spoon, about 5 minutes. Off heat, add remaining 3 tablespoons butter, remaining 1 tablespoon brandy, and any accumulated steak juices. Season with salt to taste. Set steaks on individual plates, spoon portions of sauce over steaks, and serve immediately.