1.Place tofu on a large plate lined with paper towel; top with another piece of paper towel and another plate. Stand, tilted, for 10 minutes to drain. Cut tofu into 2cm thick pieces; pat dry with paper towel.
2.Place noodles in a heatproof bowl; cover with boiling water. Stand for 2 minutes; drain. Rinse under cold running water; drain.
3.Pulse peanuts and nori in a small food processor until a semi-coarse crumble forms. Stir in sesame seeds. Lightly coat tofu in egg white, then coat in the peanut mixture. Heat 1.5cm oil in a heavy-based non-stick frying pan over medium heat. Shallow-fry tofu, in batches, for 2 minutes on each side or until golden and cooked through. Drain on paper towel. Keep warm.
4.Heat extra oil in a wok over high heat; stir-fry garlic and ginger for 1 minute or until fragrant. Add combined cornflour, soy sauce, oyster sauce and mirin to wok with remaining ingredients; stir-fry until sauce boils and thickens slightly, and vegetables are tender but still crisp. Remove from heat. Stir in noodles.
5.Top stir-fried vegetable and noodle mixture with tofu; sprinkle with extra sesame seeds, if you like. Serve straight away.
Peanut and nori mixture can be made a day ahead. Store in an airtight container at room temperature.