Preheat oven to 220C/420F. Slice cabbage into 1 inch wedges and cauliflower into small florets. Line a baking tray, and place the cauliflower on one side, and the cabbage on the other.
Mix 4 tbsp soy sauce with 4 tbsp oil and drizzle over all vegetables.
Place vegetables in the oven. After 15 minutes, remove cauliflower. Allow the cabbage to bake for another 5-10 minutes until caramelized.
Bring a large saucepot of water to the boil, then add the Udon noodles. These typically take 8 minutes, but check packet instructions. When done, drain and rinse noodles and set aside.
Mince garlic. Finely slice the spring onions and set aside a small handful for garnish. Heat remaining 2 tbsp oil in a large frypan and add garlic and remaining spring onions. Stir for 3 minutes over medium heat, then add noodles, mirin and curry powder. Stir for 2 minute, then add cauliflower and cabbage.
Add 4 tbsp soy sauce, lime juice and stir gently to combine. Serve immediately in bowls and garnish with spring onion and sesame seeds.