Add the sliced onion, cover and gently cook until softened. Cut the onions in half lengthwise; thinly slice crosswise (you should have about 8 cups/2 L). For the soup, melt the butter in a medium saucepan over a low heat. Pour in 1/2 cup of the broth and bring to a boil. Add the onions and sugar; cook, stirring often, until very soft and coloured, about 30 minutes. 2. Method. 1 1/4 cups (300 mL) shredded smoked Cheddar cheese (about 4 oz/125 g) 1. In a large heavy saucepan, melt the butter over medium heat. Authentic French Onion soup with dried bread and cheddar cheese in bowl – License high-quality food images for your projects – Rights managed and royalty free – 12404002