French Onion and Apple Soup

Melt the butter in a roasting pan over medium-high heat. Add the onion to the pan; cook for 5 minutes, stirring frequently. Continue cooking for 50 minutes or until dark golden brown, stirring occasionally. Add pepper, apple, thyme sprigs and bay leaf; cook for 3 minutes or until apples are tender. Add the wine; cook for 2 minutes, scraping off the pan to avoid browning the pieces. Add stock and cider; bring to a boil. Reduce the heat and simmer for 45 minutes. Discard the bay leaves; add the vinegar.Preheat the grill.Place the bread cubes in a single layer on the jelly pan; bake for 2 minutes or until lightly browned, turning in 1 minute.Preheat the oven to 500 degrees.Pour 1 cup of soup into each of 10 heatproof soup bowls. Spread the croutons evenly over the plates and sprinkle each serving with about 3 tablespoons of cheese. Place the bowls on a jelly roll tin. Bake at 500 ° C for 8 minutes or until the cheese is melted. Garnish with thyme leaves if desired.