Here is the recipe in James Beard’s words, with my changes in parentheses. Not saying that I know better than James Beard, but I have found I like it better with a few changes.
2 large ripe tomatoes, peeled and cut into sixths (I dice my tomatoes and I don’t peel them)
1 medium onion, peeled and ringed (I slice mine very thinly and then dice)
4 tablespoons olive oil
1 tablespoon white wine vinegar (I use red wine vinegar)
Lots of freshly ground black pepper
1/2 pound green noodles (I use whatever kind of pasta I have available–I prefer linguine)
2 tablespoons chopped fresh basil, if available
Chopped parsley (lots!)
Mix the tomatoes, onion, olive oil, and vinegar. Sprinkle with lots of pepper, and let sit for at least an hour, to give the onions a chance to lose their sharpness.
Cook the pasta in boiling water, and drain. Spoon the cold sauce over the hot pasta, and sprinkle with fresh basil and parsley. (I also add crumbled Parmesan).