Make the spread by placing the mayonnaise, mustard, horseradish, chives, cornichons, and honey in a medium bowl. Whisk to combine and refrigerate until ready to use.
Pat the steaks dry with paper towels.
Thoroughly season the steaks with salt and pepper.
Heat olive oil in a large skillet over medium-high heat.
Once hot, add the steaks, and sear for 3 to 4 minutes per side (for medium to medium-rare, depending on the thickness of your steaks).
Remove the steaks from the skillet and set aside to rest for 5 minutes.
Reduce the heat to medium. Add the butter to the skillet and melt.
Once melted, add the garlic and shallots, and saute for 3 minutes or until the shallots have begun to soften and turn golden.
Add the Worcestershire sauce and paprika to the skillet, stir to combine, and continue to saute for 3 minutes. Set aside.
Preheat the oven to broil on low.
Once the steaks have rested, slice them into thin strips.
Place the ciabatta bottoms on a foil-lined baking sheet and spread with some of the horseradish spread.
Divide the sliced steak between the dressed rolls.
Divide the Brie between the rolls, placing on top of the steak.
Place the baking sheet into the oven and broil for 2 to 3 minutes, or until the Brie has melted.
While the baking sheet is in the oven, apply the horseradish spread to the roll tops.
Remove the baking sheet from the oven and top the melted cheese with the sauteed shallots and garlic.
Top the shallots and garlic with the marinated tomatoes.
Top the tomatoes with the arugula.
Cap the sandwiches with the dressed top rolls and secure with a toothpick before serving.