Pat the steaks dry and coat in oil and salt. Heat a large skillet or grill to high heat. When hot, add the steaks and sear well on each side, about 3 minutes. Lower the heat to medium and cook until an instant-read thermometer reaches 130°F for rare, 140°F for medium rare and 150°F for medium-well.
Remove the steaks from the pan and rest for 5-10 minutes before slicing very thin.
Place the noodles in a large bowl and cover with boiling water. Soak for 10 minutes, until tender, then drain and rinse the noodles under cold water.
Heat the beef broth to a bare simmer in a medium saucepan.
Divide the cooked noodles between bowls, cover with warm broth and top with sliced steak, herbs, lime wedges, jalapeño slices, bean sprouts and onion. Stir in hoisin sauce and/or sriracha if you like.