Bring a large pot of water to boil, add a pinch of salt, and udon noodles. Cook for 6-8 minutes. And remove from the hot water to avoid overcooking. You can add them in an ice-bath if you will cook them later or directly add them to the veggies.
Heat oil in a pan, add ginger and garlic paste, cook for 2 minutes on medium heat. Add mushrooms, carrots, and bell pepper, cover, and cook for 3-4 minutes.
Add the spinach leaves and mix well. Cook for another 2 minutes.
Add the cooked udon noodles to the pan, mix in the light and dark soy sauce.
Season with salt. Turn off the heat and dress with truffle oil and sesame seeds when serving.
