The most important thing? It's one of the easiest, quickest, and cheapest things you can make. You just need some pasta, veggies, protein (optional), and a few simple ingredients for a sauce.
I took a basic sauce idea from the Rachel (of the Ray kind) and made it work for what I had on hand. First, the pasta. I had some leftover whole wheat fettucini from earlier in the week (still not sure why I hadn't thrown it out) which wasn't quite enough for my family, so I just added a packet of ramen noodles (yep, that stuff from college . . . I keep it on hand for lo mein, or for a crunchy ramen "cake" to serve under stir fry . . . that's a recipe for another time though). If you frequent an Asian supermarket, you can get some extra-tasty noodles to use in this dish. With cooked pasta in hand, I heated my wok to high, then threw in some small slivers of chicken breast (one breast for the whole family). I seasoned lightly with some salt and pepper and removed it from the pan as soon as it was just cooked. Next, I added a little garlic and ginger (if you don't have fresh on hand, just add some dry to the sauce) to the pan along with some thinly sliced carrots. I put a little water in the pan, covered, and steamed just until the liquid evaporated. This is a good tip for cooking "harder" veggies like carrots, broccoli, or sugar snap peas that need a little pre-cooking. After the steaming, I dumped in some rehydrated shiitake mushrooms (this is a great thing to keep in your pantry), button mushrooms, sliced green peppers, spring onions, and a little chopped bok choy - all stuff just hanging out in the frig. Once the veggies cooked for a minute or two, I scooted them over to one side of the pan, dumped in a couple of beaten eggs, then scrambled them before mixing the veggies back in. Make sure you let the eggs cook a little before you start stirring if you want some nice chunks of eggs instead of itty bitty pieces. All that was left to do is throw the meat back in, toss in the pasta, and dump the sauce on. The sauce is super simple - equal parts of hoisin sauce, soy sauce, and water, mixed with a little sesame oil. I added a little Srirachi for heat too. Finis! The sauce is super-versatile though . . . Option 1: Add a little sugar to the sauce, then some toasted cashews or sesame seeds on top of the stir fry. Shrimp would be an excellent protein choice for this one. Option 2: Add a little peanut butter to the sauce, some chopped peanuts and cilantro on top. It's like your own Pad Thai! By the way, the starch from the pasta will thicken the sauce some, so make sure you take that into account when you're making it. If it ever gets too thin and soupy though, you can always thicken with a little cornstarch or lightly flour your chicken/shrimp/whatever before cooking it to thicken the sauce later.
Here are some suggested ingredients for your own lo mein, just so you won't be staring into your OWN frig wondering, "I wonder what I could do with this??" Just mix and match and have fun! Use your "take-out" money for a movie instead! :-)
Onions (spring or yellow)
Cabbage (choy or green)
Mushrooms (any kind)
Sugar snap peas
Beef (even leftover steak)
Pork (how about leftover pork chops??)