How to Make It
Heat sunflower oil in a medium saucepan over medium-high; add garlic, and cook, stirring often, 1 minute. Add tomatoes, soy sauce, chiles, sugar, and salt. Cook, stirring occasionally, until tomatoes are mashed, 8 to 10 minutes. Let cool 30 minutes. Place in a mini food processor, and process until smooth. Set aside.
Heat canola oil in a large skillet over medium. Add white onion, garlic, ginger, and salt; cook, stirring often, 30 seconds. Increase heat to medium-high; stir in spring onions, cabbage, carrot, and chile. Cook, stirring occasionally, until just softened, 3 to 5 minutes. Remove from heat; stir in cilantro, and let cool slightly.
Place about 2 teaspoons filling in center of each dumpling wrapper. Gather up and pleat edges of wrapper around filling to enclose; pinch top to close up like a little satchel.
Fill a pot with 2 inches of water, and bring to a boil over high. Place a bamboo steamer lined with parchment paper over pot; pierce parchment 10 times with a skewer. Working in batches, place momos in basket, and steam, covered, until momos are transparent and do not feel sticky, 8 to 10 minutes. Cover to keep warm. Serve with red chile chutney.
Find red and green Thai chiles in the refrigerated section of the grocery store.