In a Dutch oven, heat 2 tablespoons of olive oil and 1 tablespoon of butter over medium heat. Add 8 cups of thinly sliced onions and sauté for 10–13 minutes until softened and translucent.

Reduce the heat to medium-low and allow the onions to cook slowly, stirring occasionally for 30–40 minutes until they turn a deep golden brown.

Add 3 minced garlic cloves and cook for an additional 2 minutes until fragrant.

Stir in 1/2 cup of port wine or dry sherry, bring to a boil, then simmer for 5 minutes to reduce the liquid by half.

Pour in 64 ounces of beef broth, 1/2 teaspoon of pepper and 1/4 teaspoon of salt. Stir well, return to a boil, then reduce heat to low and cover. Simmer for 1 hour.

Preheat your oven to 400°F. Arrange 24 slices of French bread baguette on a baking sheet and brush each side with olive oil. Bake for about 3–5 minutes on each side until golden.

Rub the cut side of a halved garlic clove over each baguette slice after toasting.

Ladle the soup into broiler-safe bowls, top each with 2 toasted baguette slices, and sprinkle 3/4 cup of shredded cheese on top. Broil for 2-4 minutes until melted and bubbly.