Preheat the oven to 425°F. In a medium skillet, heat the EVOO over medium-high heat. Add the steak and cook until browned, 5 minutes. Transfer to a plate. Add the butter to the skillet to melt, then add the mushrooms and cook for 2 minutes. Add the onion and garlic and cook until softened, about 5 minutes. Sprinkle in the flour and cook, stirring, for 1 minute. Stir in the beef stock, peas and Worcestershire sauce. Return the meat to the pan and cook until the sauce thickens and the peas heat through, 2 to 3 minutes. Season with salt and pepper; remove from the heat.