Tomatoes: Halve the tomatoes horizontally.. Scoop out the seeds and reverse the empty halves on paper towels to drain.
Persillade: Toss together the parsley, garlic and breadcrumbs in a bowl. Drizzle on the vinegar. Fill the tomato halves with this mixture and set in a buttered baking dish. Spoon the butter over each filled tomato half.
Bake for 15 to 20 minutes, until the tomatoes are just tender. Serve hot.
*Panko: Japanese bread crumbs that are lighter, crisper an absorb less oil than other crumbs.