Bring a saucepan of water to the boil and add the udon noodles. Boil for 2 to 3 minutes or according to the instructions on the packet. Drain well and rinse with cold water. Set aside.
Heat the olive oil and sesame oil in a wok or large skillet, then add tofu and onions, cook until lightly brown. Add carrots, ginger, garlic mushrooms and cook for a few more minutes until mushrooms start to brown.
Mix soya sauce, hoisin sauce, sriracha and stock, let sit for five minutes before stirring it into the wok and bring to the boil. Add noodles to the wok, cook until noodles are heated through. Spoon into serving bowls and garnish with green onions and serve hot.
Instead of the tofu you can use chicken breast fillets cut into strips and instead of the vegetable stock you can use chicken stock.