French onion soup with cheesy croutons

Peel the onions, cut them in half, and then slice them into slices about half a centimeter thick.

Heat the butter and oil in a large pot, then add half of the onions. Sauté intensely and quickly until golden brown in places. The color is key, so stir constantly. If it starts to burn, add a few tablespoons of water to deglaze the pan. Repeat this 2-3 times until the onions are evenly golden brown.

When the first batch of onions is browned, add the remaining onions and let them soften, stirring constantly. This part does not need to be browned, which will make the texture of the soup more exciting. Finally, add the sugar and stir for another minute until dissolved.