1. Finely slice 1 1/2 lbs. of onions.
2. Heat oil in a large heavy saucepan (or Dutch oven) over a medium low heat and add onions. Stirring frequently, sauté for 30-40 mins. Onions should caramelize to a medium brown.
3. While onions caramelize, shred cheese.
4. After the onions have caramelized, raise the heat to medium high, add the white wine, and cook for 10 mins. to burn off the alcohol.
5. Add vegetable stock and herbs, bring to a boil, and cook for 20 mins. uncovered.
6. Dissolve cornstarch in 1/4 c. of water and add to soup.
7. Add heavy cream and stir.
8. Remove herb sprigs from soup and taste for salt. Add more if necessary (there will already be a fair amount of salt in the soup from the vegetable stock if store bought).
9. Add black pepper, bring soup to a boil again and cook for 5 mins.
10. Ladle soup into two bowls, and sprinkle 1/4 c. of the shredded cheese directly onto the top of each bowl.
11. Toast the slices of bread twice (do not burn them), cut them into cubes and place cubes on top of each bowl.
12. Sprinkle the remaining cheese equally over the top of the bread in each bowl.
13. Broil the soup in an oven for 2-3 mins. melting the cheese.
14. Serve immediately with a side dish that is crisp, raw, light and acidic.