French Onion Soup

Direction :

Heat oil in a large, heavy pot over medium. Add onions and cook, stirring occasionally, until soft and beginning to turn golden, 35 to 40 minutes (if onions develop color quickly, reduce heat).
Add butter and seasonings and cook:
Add butter, garlic, thyme, bay leaf, 2 teaspoons salt, and 1/4 teaspoon pepper. Cook, stirring a few times, until golden brown, 15 to 20 minutes more.
Add vermouth and boil, then add stock and Marsala and simmer:
Add vermouth and boil, scraping up browned bits from bottom of pot, until mostly evaporated, 1 to 2 minutes. Stir in stock and Marsala. Bring to a boil, then reduce heat to low and gently simmer 45 minutes. Season to taste.
Preheat broiler: divide soup between bowls, add toast and cheese and broil:
Preheat broiler. Ladle soup into broiler-safe crocks or bowls set on a rimmed baking sheet. Nestle a piece of toast into each, partially submerged, and top each with 1/3 cup Gruyère. Broil until cheese is melted, bubbly, and golden brown in places, 2 to 4 minutes.