COOKING INSTRUCTIONS Let the steaks come to room temperature, about 30 minutes.
Preheat oven to 400°F/204°C.
Place an oven-safe, glass baking dish in the oven to warm up.
Heat a large cast-iron skillet on medium-high.
Brush melted butter onto one side of the steak.
When the skillet is ready, add the steaks.
While the first side is browning, brush the other side with butter.
Once a nice brown crust forms, about 2 to 3 minutes, use tongs to flip the steaks and sear the other side.
Using tongs transfer steaks to the warm dish in the oven and roast for 6 to 8 minutes for medium-rare.
While the steaks are roasting, make your sauce.
Add 1 tablespoon/15 ml of butter to the same cast-iron skillet used to brown the steaks.
Add the shallots and season generously with salt and pepper.
Continue to cook until the shallots are softened, about 10 minutes.
Add the vinegar and cook until it evaporates.
Add the broth and bring to a boil. Allow the sauce to cook until it has reduced by half. Pull the pan from the heat, stir in the remaining tablespoon of butter and rosemary.
Remove steaks, salt and pepper and let rest for 5 minutes.
Serve topped with shallot sauce.