- Over medium heat, warm oil in a large stockpot or Dutch oven.
- Add onions and cook for 15 minutes, stirring occasionally, until lightly browned.
- Reduce heat to low and let simmer, stirring occasionally.
- Cook for 35-45 minutes until onions are a deep, golden brown.
- Add Roasted Garlic Onion Jam, broth, salt and pepper and bring to a boil.
- Reduce heat to low and simmer for 20-25 minutes.
- Ladle soup into 4 heatproof bowls. Top with toasted bread slices and grated cheese.
- Broil 2-3 minutes until cheese is bubbly and browned.
- Garnish, if desired, with fresh chives, parsley or thyme.