Philly Cheesesteaks

Bahan-bahan (2 porsi)

• 1 pound ribeye steak (or round steak or sirloin)
• ½ large white onion (or 1 small white onion, thinly sliced)
• 1 tablespoon butter
• salt and black pepper (to taste)
• 1 tablespoon olive oil
• 2 hoagie rolls
• 2 tablespoons garlic butter
• 3 ounces provolone cheese (or American cheese, sliced)