Trim off and discard the stems of the artichokes, leaving about 1/2 inch. Scrub the artichokes clean under running water. Using sharp scissors, cut 1/2 inch off the top of each leaf, and with a very sharp knife slice about 1-inch off the top of the artichoke.
To a large kettle of boiling salted water, add 2 or 3 whole garlic cloves and 1 tablespoon of olive oil. Cook the artichokes, covered, for 45 to 55 minutes, or until tender. Remove them carefully with tongs or a big slotted spoon, and place them upside-down on a rack to drain as they cool.
To make the filling, cut the tomatoes into 1/4-inch dice and chop the remaining garlic. Mix the tomatoes and garlic with the chopped herbs, 1/2 teaspoon of salt, 1 1/2 tablespoons of olive oil, and a touch of vinegar or lemon juice if you want it. Stir in most of the bread crumbs, check the consistency, then stir in more as needed to make a fairly thick mixture. Finally, add the Parmesan.
When the artichokes are cool enough to handle turn them right side up and gently pull open the leaves from the center of each one. Pull out the thin leaves from the very center and then scrape out the fibrous choke with a teaspoon.
Spoon some of the filling into the center cavity of each artichoke, then spoon a bit more here and there between the leaves. Distribute it evenly between the 6 artichokes, using about 2/3 cup for each. A little bit more olive oil can be drizzled over the artichokes just before serving.
Serve these at room temperature or chilled, and don't hold them longer than 3 or 4 hours.
Recipe courtesy of Anna Thomas, The New Vegetarian Epicure, Knopf, 1996