Classic French Onion Soup made at Home with minimal ingredients.
Into a STAUB 4-QT ROUND COCOTTES melt butter over medium heat. Add onions. Sprinkle with sugar. Stir to coat and arrange into as single a layer as possible.
Allow to cook until onions are golden and start to caramelize, stirring as little as possible for approximately 30-45 minutes.
Add flour. Stir to combine. Add Marsala, beef stock. Season with salt, pepper and thyme. Stir to combine. Reduce heat to low and simmer for approximately 15-20 minutes, stirring as necessary.
Preheat broiler. Toast baguette slices.
Ladle soup into ramekins. Top each with a toasted baguette and grated cheese. Return to broiler just until cheese has melted.
Garnish with additional thyme if desired.