Grind peppercorns coarsely using a coffee grinder or mortar and pestle.
Season steaks on both sides with peppercorns and salt.
Heat butter and oil in a large cast iron skillet over medium-high heat. Cook steaks until browned, about 5 minutes per side. Transfer steaks to a plate and tent with aluminum foil.
Remove skillet from heat and drain grease. Pour in 1/3 cup brandy. Light brandy carefully using a long match. Shake skillet back and forth until flames die down, about 30 seconds.
Return skillet to medium heat. Whisk in cream; bring to a simmer. Cook, whisking occasionally, until sauce coats the back of a spoon, 5 to 6 minutes. Stir in 1 teaspoon brandy. Return steaks to the skillet; cook until heated through, 1 to 2 minutes.
Use extreme caution when igniting the brandy in step 4. Use a long match such as a fireplace match or long barbeque lighter. Ignite the fumes at the edge of the pan, not the liquid itself. Do not lean over the skillet as you ignite the fumes.