Rub the meat with the olive oil, chopped rosemary, salt and pepper, place on a foil-lined baking pan. Bring the meat to room temperature for at least 30 minutes or up 2 hours before cooking.

To caramelize the onions, in a large skillet over medium-high heat, add the olive oil and butter along with the bay leaves. Once the butter has melted add in the thick-sliced onions, season with salt and pepper, and cook for 3 - 5 minutes.

Pour the vinegar into the skillet and turn the heat to low and allow to cook with lid askew for about 20 - 25 minutes or until tender. (Do not turn onions, allow to only cook on one side).

Place the rack in the middle of the oven and preheat the oven to 450°F.

Roast the meat for about 8 - 9 minutes (about 3 minutes per pound), turn the heat off, leaving the meat in the oven without opening the oven door for 20 minutes for medium-rare or 25 minutes for medium.

Remove the meat from the oven, transfer to a cutting board, cover with foil and allow meat to rest at room temperature for 10 -15 minutes before slicing thinly.

Slice the Ciabatta lengthwise and toast in a dry skillet over medium heat until brown if desired.

Spread on Maille Dijon Originale to taste on toasted ciabatta.

Top with caramelized onion, sliced meat, and arugula.