Cut the watercress into 5cm lengths. Slice the onion thinly.

Trim the root of the shimeji mushrooms and separate them. Slice the thick-cut bacon into strips.

Heat butter in a frying pan until melted, then sauté the onion until softened.

Add the bacon and shimeji mushrooms to the pan and mix well.

Pour in the water and bring to a boil. Add the granulated consomme and stir to combine.

Break the spaghetti in half and add to the pan. Cook according to the package instructions.