Peel the squash and cut it into medium-sized cubes. Place the pieces of squash in a baking dish covered with baking paper. Drizzle with olive oil and bake for 30 minutes at 200°C.
Wash and thickly slice the mushrooms. Dice the tofu. Fry the tofu in a pan with a little sesame oil for 5 minutes, then add the mushrooms and fry for another 5 minutes.
Cook the soba noodles according to the instructions on the package. Set aside.
Wash the spinach. Finely chop the green onions.
Prepare the sauce: in a bowl, whisk together the soy sauce, honey and finely chopped ginger. Add a small amount of water. Optionally, add the sriracha sauce.
In the pan, add the cooked squash and mix. Stir in the cooked soba noodles and pour in 1/3 of the sauce. Stir well and reheat if necessary.
In a large bowl, serve the noodle, vegetable and tofu mixture. Place a handful of spinach shoots, sprinkle with chopped green onions and sesame seeds. Add a little sauce to taste and enjoy.