Preheat the oven to 350ºF. Quarter the squash, seed and toss with one tablespoon of oil and a pinch of sea salt and black pepper, then roast on a baking sheet for one hour, or until soft and golden. Leave to cool.
Peel the garlic and two centimeters 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 one heaping 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 2/3 cup 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 chili, and place in a small dipping bowl. Trim and finely shred the scallions, toast the sesame seeds, then serve with soy, mustard and lime wedges.