Season the top sirloin steaks with the salt and pepper and allow to rest at room temperature for 20-30 minutes.
In a small bowl, whisk together the pepper, honey, and 1 Tablespoon of the olive oil until combined. Season with salt if desired.
Heat a 12" cast iron skillet on medium-high heat for about 5 minutes. Prepare the sirloin by coating the steaks in 1 tablespoon of olive oil before transferring them to the cast iron skillet.
Cook the steak for about 5-7minutes, flipping halfway through, until there is a nice crust on the outside and the meat is cooked to your desired doneness. (We prefer a good medium rare cook for this dish. The meat will continue to cook when you transfer the meat to your platter or cutting board.)
Allow the meat to reston a cutting board for a few minutes while you cook the mushrooms.
Carefully clean out the skillet ( you may use a paper towel) and add the remaining oil and mushrooms, turning the mushrooms to coat them with the oil. Cook the mushrooms for about 5 minutes, or until they are browned and starting to crisp.
Stir the mushrooms to cook the remaining sides and the entire mushrooms are browned (about another 5 minutes).
Remove from heat and add the shallots and garlic, cooking for another minute or so, until the shallots have softened.
Slice the top sirloin steaks and spoon the mushroom mix over the slices. Drizzle with the pepper vinaigrette and serve. Taste and season with salt if necessary.
Serve immediately.