[stingo]

From philadelphia.about.com:

Most people who visit Philadelphia can't leave without trying a Philadelphia cheesesteak. Here are some tips so you can make your own at home.
Difficulty: N/A
Time Required: 15 minutes
Here's How:

1. Start with good beef. Pat’s uses sliced rib-eye. Jim’s uses USDA choice top round western steer beef.
2. Shave the beef very thin so it cooks quickly and remains tender.
3. Use a fresh high quality Italian roll - Amoroso’s is a favorite.
4. Decide if you want your steak with or without fried onions.
5. Decide if you want a steak or a cheesesteak. If you elect a cheesesteak you need to decide on American cheese, provolone or the Philly favorite "cheez whiz."
6. Any add-ons? Mushrooms, peppers, pizza sauce, tomatoes? You decide. It’s your sandwich.
7. Start to cook. Sauté the onions, peppers and mushrooms until soft.
8. Fry your steak until brown but not crispy or burned. You can mix in the fried vegetables now or add them at the end.
9. If you elect American cheese or provolone place the cheese on the meat until slightly melted. If you choose Cheez Whiz just smear it on the roll.
10. Place the roll over the meat/cheese/vegetables and scoop it into the sandwich.
11. Garnish your sandwich with pizza sauce, hot or sweet peppers or pickles as you choose.
12. Enjoy your Philadelphia cheesesteak.

Tips:

1. Using the best beef available is the key.
2. Don't overcook the ingredients.
3. If you don't cook, go to Pat's, Geno's or Jim's. Which one is best? It's a regular Philadelphia debate.