Pat the steaks dry and season with salt and pepper. In a heavy-duty 12-inch skillet (preferably cast iron), heat 2 Tbs. of the olive oil over high heat until shimmering hot. Cook the steaks in a single layer, flipping with tongs halfway through, until an instant-read thermometer inserted in the thickest part of the steak registers 130°F for medium rare, 5 to 7 minutes total (if necessary, lower the heat to medium high to finish cooking the thicker pieces). Transfer to a plate and let rest, loosely covered with foil, while making the sauce.
Heat 2 Tbs. of the olive oil in the skillet over medium-high heat until shimmering hot. Add the mushrooms and a generous pinch of salt and cook, stirring occasionally with a wooden spatula, until golden-brown, 6 to 8 minutes. Transfer to a bowl and keep warm.
Lower the heat to medium, add the remaining 1 Tbs. olive oil, the shallot, and thyme and cook, stirring, until the shallot is slightly browned, about 1 minute. Add the wine and cook, stirring and scraping the bottom of the pan to dissolve any browned bits, until the liquid has almost evaporated, about 1 minute. Add the chicken broth. Raise the heat to high and boil, adding any juice that has accumulated from the steak and mushrooms, until the sauce is reduced to about 1/3 cup, about 7 minutes.
Remove the pan from the heat and whisk in the butter. Stir in the mushrooms and season the sauce to taste with salt and pepper.
Thinly slice the steaks diagonally across the grain, if you like, and serve topped with the mushroom sauce.