Get a wok if you don't have one...
I've had woks over the years but I'm not crazy about their utility; as Alton Brown would say, they're uni-taskers. A large non-stick skillet works fine and is more versatile. Now I do all my stir-frying in a enamel/cast iron braiser, it works great and can do a lot more besides.
^Oh, nothing beats fresh tomatoes. With some produce there's not really a difference between grocery store and fresh, but tomatoes taste like a whole different fruit. There the one thing I will never buy at the grocery store, only the farmer's market. Unfortunately, I don't get enough sun to grow them myself. My mom used to grow them, and one of my favorite things was a tomato right off the vine cut in half and sprinkled with sugar.
Agreed 100%. I will not buy a tomato in the winter, no matter what, and in the summer we grow our own. I have eight plants growing now, they will go in the ground this weekend.
We buy canned tomatoes by the case, though; they are useful in all kinds of recipes and are harvested when ripe, unlike supermarket produce tomatoes which are harvested green and hard.