French Onion Soup with Meatballs (or Not)

1. In a large saucepan over medium heat, melt the butter and then add the olive oil. Add the onions and cook for about 30-40 minutes, stirring occasionally, until very soft, medium brown and caramelized. Add the sugar about 10 minutes into the cooking to help the onions cook down.
2. Then stir in the garlic and dried thyme. Cook for about two minutes longer.
3. Stir in the flour. Cook for another minute or so.
4. Add the vegetable broth, Worcestershire sauce, salt, pepper and bay leaf. Bring to a boil, then turn the heat to low and simmer, covered, for about an hour. Continue to simmer over low heat while preparing the meaty half of the soup. Skip to step 8 if you’re not making the meaty half.
5. Meanwhile, make the meatballs. In a medium bowl, using a fork, mix together the ground beef, bread crumbs, egg, garlic, Parmesan cheese, salt and pepper until all ingredients are well-incorporated. Scoop out tablespoonfuls, roll into balls, and set aside (I place them on a sheet of wax paper).
6. After the soup has cooked for an hour, into another large saucepan over medium heat, transfer two cups of the soup plus another 1/2 cup or so of the onions with a slotted spoon. Add the two additional cups of broth (either beef or more veggie). Bring to a boil then turn to a simmer.
7. Carefully drop the meatballs into the meaty soup and continue to simmer, uncovered, for 20 minutes until meatballs are cooked through.
8. Butter the French bread on both sides and place on a cookie sheet. Broil in your oven on high heat until golden brown; turn over and brown the other side. Remove from the oven, but keep the broiler on.
9. Ladle the vegetarian soup into three oven-proof bowls, and ladle the meaty soup into three bowls as well. Reserve three meatballs to place on top of the soups with meat. Place one piece of French bread on top of each bowl of soup, then sprinkle each with 1/4 cup mozzarella and 1/4 cup Gruyere. Cut the meatballs in half, and place two halves on top of each bowl of meaty soup.
10. Carefully place the bowls on a cookie sheet and broil on high until the cheese is melted and bubbly, then serve.