Australian Steak Sandwich

Preheat the grill or stovetop to medium-high heat.
Season the sliced steak with salt and black pepper.
Grill or cook the steak until it is cooked to your liking.
Meanwhile, heat some olive oil and butter in a frying pan and caramelize the sliced onions until they are soft and golden brown.
Slice the hoagie rolls or baguettes lengthwise.
Place a slice of cheddar cheese on the bottom half of each roll.
Add the cooked steak on top of the cheese.
Top with caramelized onions, lettuce, and sliced tomato.
Spread some tangy sauce (optional) on the top half of the roll.
Close the sandwich and press it lightly.