Heat the olive oil over medium heat in a large saucepan. Sauté the onion, ginger, garlic, lemongrass, and chili pepper for 3 minutes until lightly browned.
Add the butternut squash and stock, and bring the mixture to a boil. Lower to a simmer and cook for 35-40 minutes, stirring occasionally until all the vegetables are tender. Add the chopped tomato, minced cilantro, and lime juice. Serve with additional cilantro for garnish, and enjoy!