French Onion Soup

Thinly slice all the sweet and red onions.

In a large pot or Dutch oven over low heat, melt the butter with the olive oil.

Add the sliced onions to the pot and cook slowly, stirring occasionally, until deeply caramelized and jammy. This can take 45-60 minutes.

Deglaze the pot with the dry sherry, scraping up any browned bits from the bottom. Cook for a minute or two until the alcohol smell has cooked off.

Pour in the beef stock, add the thyme sprigs, and bring to a simmer.

Let the soup simmer over medium heat for 15 minutes.

Ladle the soup into oven-safe bowls.

Top each bowl with one or two slices of toasted baguette.

Generously cover the baguette and soup with shredded Gruyère cheese.

Place the bowls under the broiler until the cheese is melted, bubbly, and golden brown.

Carefully remove from the oven, garnish with chopped chives, and serve hot.