Preheat the oven to 180ºC/350ºF/gas 4. Quarter the squash, deseed and toss with 1 tablespoon of oil and a pinch of sea salt and black pepper, then roast on a tray for 1 hour, or until soft and golden. Leave to cool.
Peel the garlic and 2cm of the ginger, then whiz in a food processor with the broccoli, miso and vinegar until fine. Pulse in the squash, then season to taste.
One by one, lightly wet the edges of the wonton wrappers with your finger, add 1 heaped teaspoon of filling to the middle of each, and pinch together to seal (don’t stress if they tear every now and again), placing them in a large oiled nonstick frying pan as you go. Put the pan over a high heat, then pour over 150ml of water and cover. Let it steam until the water has completely evaporated, then uncover and allow to fry, removing as soon as the bottoms are golden and crisp.
Meanwhile, peel the remaining ginger, finely grate with the chilli, and place in a small dipping bowl. Trim and finely shred the spring onions, toast the sesame seeds, then serve with soy, mustard and lime wedges.