Peel and rinse the onions. Slice in half and slice each half into crescents before cutting in half again.

Heat your soup pan and melt the butter until slightly bubbly.

Add in the onions and cook under low to medium heat, stirring occassionally until the onions are well-coated with butter.

Add the sugar and salt and continue to cook under low heat until the onions turn a golden to dark brown. You may add the mushrooms and saute slightly at this point.

IMPORTANT NOTE: Be patient if the caramelizing of the onion slices take a while. You do not want high heat and risk burning your onions. :)

Add the water and bouillon cube. Alternatively, you can use beef or chicken stock if you have it available.

*Note: Prepared store-bought stock is not readily available in the Philippines versus beef or chicken cubes, making this the usual option for Pinoy cooks. :)

Keep at medium heat and boil for about 15-30 minutes, adding the ground pepper in and whatever additional spices you would like. The longer you boil, the more flavorful the soup will be.

While the soup is simmering, slice your pan de sal (or bread of choice) horizontally into 1/4-inch thick slices. This will be your soup's "topping".

Turn off the heat once soup is cooked down to desired flavor.

To serve, crack a whole egg into your soup bowl and pour your hot soup over it. Top with your bread slices.