How to Make French Onion Soup:
Cut onions in half, cut off the ends, then peel and slice onions thinly (cut parallel with the grain of the onion).
In a large heavy-bottomed pot or dutch oven over medium heat, add 2 Tbsp olive oil and 2 Tbsp butter. Add sliced onions and sauté uncovered, stirring occasionally for 10 minutes.
Sprinkle the onions with 1/2 tsp sugar which will help the onions caramelize faster. Sauté uncovered for another 30-40 minutes, stirring occasionally until onions are caramelized and browned. Stir more frequently towards the end to prevent scorching or burning the onions.
Once onions are caramelized, add minced garlic and sauté another minute.
Add 1/2 cup sherry and deglaze the pot by scraping the bottom. Continue stirring until all of the sherry has cooked out (about 3 minutes over medium heat).
Add 8 cups beef stock, 1 bay leaf, thyme and 1 tsp salt. Partially cover and simmer for 30 minutes for the flavors to meld. Add another 1/2 tsp salt and 1/2 tsp black pepper, or season to taste then remove from heat.
How to Make Crouton Topping:
While soup is finishing up, preheat oven to 400˚F. Slice baguette to 1/2” thick slices. Brush both sides lightly with olive oil, arrange on a baking sheet and bake for 6-8 minutes until golden brown at the edges.
Once the soup is ready to serve, top the toasts with half of the cheese and broil for 2-3 minutes until the cheese melts and turns golden in spots.
Pour soup into warm bowls and sprinkle remaining cheese over the hot soup. Top with hot cheesy toasts then serve.
