French Onion Soup au Gratin


Today, I will prepare a French onion soup au gratin. Onion soup was already popular in ancient Rome. It was then considered a dish for modest people. Today, the reputation of this soup is well established. Many of us love it. A member of my extended family loves it so much, he enjoys comparing this soup from restaurant to restaurant.


  • 2 tbsp. olive oil
  • 1 tbsp. butter
  • 6 onions sliced into thin half rings with the pieces separated from each other
  • between 6 and 8 cups of water
  • 2 tbsp. dried thyme
  • salt and pepper to taste
  • a few finely chopped basil leaves (optional)
  • a few slices of crusty bread
  • 1 1/2 cup mozzarella cheese
  • 1 sliced green onion to garnish


In a medium-sized, heavy-bottomed pot, heat oil over medium-high heat. Add the butter and the onions. As soon as the onions have softened, increase the heat to high and sauté the onions (about 8 minutes), stirring occasionally.

Reduce the heat to moderate, deglaze the pot by adding about 1 cup of water and scraping up the bottom with a wooden spoon. Pour in the rest of the water, then let simmer for about 5 minutes.

Add thyme, salt and pepper, then mix well.

Ladle 2-3 ladles of soup into onion soup bowls, add basil leaves and crusty bread. Cover everything with cheese.

Put the bowls in the oven and broil for a few minutes until the cheese is nicely coloured.

Before serving, add the green onion.