Pull the basil leaves from the stalks, rinse briefly in cold water, and shake or spin dry. Tear all but the tiniest leaves into small pieces, holding back a small amount to add later.
Put the tomatoes, chopped garlic, olive oil, salt, and several grindings of pepper in a saucepan over medium-high heat. Cook 20 to 25 minutes, until the oil floats free from the tomato. Taste and correct for salt.
Take the pan off heat and mix in the torn basil. Add the reserved basil when tossing the sauce with pasta.
