Thinly slice the onions.

Heat a frying pan and melt the butter.

Sauté the onions until they turn golden brown. Tip: Avoid stirring too much. Stir only when the color changes, and repeat this process.

It takes about 20 minutes to achieve a golden brown color. (This may vary depending on the heat and quantity.)

Add water, bay leaf, and bouillon cube, and simmer for 7-8 minutes.

While simmering, slice the baguette to your preferred thickness and lightly toast it.

Pour the soup into cups or bowls, and place the baguette on top.

Top with cheese and broil in a toaster oven or similar appliance until the cheese is golden brown.