Preheat the oven to 200°C (390°F) using conventional oven settings (top and bottom heat). Press the tofu to remove as much liquid as possible, then cut it into cubes or tear it into small pieces. In a bowl, toss the tofu pieces with cornstarch, oil, and a generous pinch of salt. Spread the tofu onto a baking sheet lined with parchment paper and bake at 200°C (390°F) for 20 minutes, or until the cubes are golden brown and slightly crispy on the outside.

Meanwhile, wash or peel the carrots and coarsely grate them. Cut the white cabbage into thin strips. Peel and finely dice the garlic, and dice the ginger as well. Slice the spring onions into rings, reserving the green parts for garnish.

Spread oil in a large pan, add the vegetables and sauté over medium heat for 5 to 10 minutes, until nicely softened. Stir occasionally.

Meanwhile, mix peanut butter, soy sauce, lime juice, sugar and sriracha in a small bowl to form a creamy sauce.

Once the vegetables are nice and soft, reduce the heat and add the pre-cooked udon noodles. Add the sauce and stir-fry for two minutes.

Once the tofu is slightly crispy and has turned golden brown, remove the baking tray from the oven and mix the tofu pieces into the noodles.

Season the fried udon noodles with salt and pepper to taste. Divide the noodles between two plates and serve with the remaining spring onions and, if desired, a few lime wedges.