Photo: Johnny Autry; Styling: Mary Clayton Carl
The slow cooker completely eliminates the stirring part of caramelizing onions; it all goes happily unattended. Freeze the bag of soup in a bowl rather than laying it flat, so it will fit in the saucepan when it's time to thaw.
1. Place butter, thyme, and bay leaf in the bottom of a 6-quart electric slow cooker. Add onions; sprinkle with sugar. Cover and cook on HIGH for 8 hours.
2. Remove thyme and bay leaf; discard. Add stock, vinegar, salt, and pepper; cook, covered, on HIGH for 30 minutes.
3. Preheat broiler to high.
4. Arrange bread in a single layer on 2 baking sheets; broil 30 seconds on each side or until toasted. Place 1 cup soup in each of 12 (8-ounce) ramekins or ovenproof bowls, or follow freezing instructions. Top each serving with 2 bread slices and about 2 tablespoons cheese. Place 6 ramekins on a jelly-roll pan; broil 2 minutes or until cheese melts and begins to brown. Repeat procedure with remaining 6 ramekins, bread slices, and cheese.