I made this into a delectable meal-in-a-bowl for four people by using deep bowls that hold 2 cups of soup each and placing a hearty baguette crouton on the bottom and top of each serving. This could easily serve eight if the portions were halved. I used a combo of sweet Vidalia and your basic yellow onions. I like store bought, sodium-reduced, liquid stock sold in cartons rather than cubes. Use all Gruyère cheese or combine it with Emmental, mozzarella, cheddar or Asiago, if desired.
5 or 6 onions (about 3 lb/1.35 kg)
2 tbsp butter
2 tbsp vegetable oil
1 tsp granulated sugar
1 tbsp balsamic vinegar
¼ cup dry sherry, port or dry white wine
4 cups chicken stock
4 cups beef stock
2 tbsp cognac (optional)
Salt and freshly ground black pepper to taste
8½-inch (1 cm) thick slices baguette
2 tbsp olive oil
2 cloves garlic, minced
2 tbsp chopped fresh parsley
2 cups shredded Gruyère cheese (about 6 oz/170 g)
Halve onions; slice thinly.
In large heavy-bottomed saucepan, melt butter with vegetable oil over medium heat. Add onions; cook, stirring occasionally, about 15 minutes or until wilted and softened. Add sugar and vinegar; cook about 50 minutes more, stirring occasionally, or until deep golden brown and caramelized. Add sherry; cook 2 minutes, stirring and scraping browned bits from bottom of saucepan. Add chicken and beef stock. Bring to boil; reduce heat low and simmer, uncovered, about 20 minutes. Stir in cognac (if using); add salt and pepper.
Preheat broiler.
Place baguette slices on baking sheet; drizzle with olive oil, then sprinkle with garlic and parsley. Place under broiler until lightly browned, about 2 minutes. Place 1 slice in each of four ovenproof soup bowls; pour hot soup on top. Place 1 remaining baguette slice on top of each bowl; sprinkle cheese on top. Place bowls under broiler until cheese is melted and bubbly, about 3 to 4 minutes.
Makes 4 generous servings.