Firstly slice the all on the onion. No need to be too fine.

Sauteed the onion in a bit of oil and the butter. Stir only once in 2-3 mins in medium high heat to promote caramelization until all the onions turn brown and soft.

Add in the garlic and thyme, cook for 3 minutes.

Then you can pour the beef stock and bring it to a boil.

While on the other pan melt the butter on medium heat. Then put in the flour and cook it to form roux.

Keep stirring the roux mixture till fully cooked to brown roux. This will give a deeper darker color and thicken the soup when we add in after.

Turn down the flame on the onion soup to the smallest before adding in the roux mixture while stirring.

Cook and keep stirring the soup gently until it thickens and the roux is dissolve around 5 mins.

Pour the soup in a small over proof soup bowl. Put in a sliced baguette or two. Put some Mozarella on top and bake for 6mins in a 220°c oven until the cheese is melted and brown. Then the soup is ready to serve.