In a bowl mix all the Teriyaki sauce ingredients together and set aside. Lightly flour tofu.
In a frying pan, heat the sesame oil, add the tofu and cook until both sides become golden brown. Remove from pan and set aside.
In the same frying pan, add a little oil, stir fry red capsicum and mushrooms. Add the tofu back into the pan and add the teriyaki sauce. Add spring onion and heat through till sauce thickens a little. Serve and enjoy!