Step 1

Preheat the oven to 375°F

Step 2

In a deep pot or Dutch oven over low heat, soften the onions in the butter and oil for about 30 minutes and cook until the onions are golden brown, then add the flour and stir

Step 3

Add the brandy (if using) and continue to stir, then add the stock

Step 4

Simmer for at least 1 hour

Step 5

Taste for seasoning and adjust as needed with salt and pepper

Step 6

Ladle into 4 ovenproof soup bowls and place the croutons on top, then sprinkle with a good amount of Gruyere cheese

Step 7

Brush the lip of each bowl with some of the egg wash

Step 8

Drape the puff pastry rounds over the bowls and press to gently seal

Step 9

Sprinkle the Parmesan on top of the pastry

Step 10

Put into the oven for about 20 minutes until golden brown