1. Core and cut a deep X across the bottom of each tomato. Place in a 2½-quart soufflé dish. Cook, uncovered, at 100% for 20 minutes, stirring once.

2. Remove from oven. Pass through a food mill fitted with a medium disc. There should be about 8 cups cooked tomatoes.

3. Return tomatoes to soufflé dish. Cook, uncovered, at 100% until almost all liquid has evaporated; this will take about 45 minutes.

4. Remove from oven. Let cool completely. Store, tightly covered, in the refrigerator or freezer (freeze in small quantities).