Preparation

• Place two layers of paper towels on a plate, then top with the tofu, then another two layers of paper towels, and a large plate. Leave for about 15 minutes to drain. Cut the tofu into 1-inch cubes. In a small bowl, stir together the brown sugar and curry paste. Add one-third of this mixture to a zip-top, gallon-size plastic bag. Add the tofu and gently coat it with the marinade, using your hands to massage it. Close the bag and refrigerate.
• Put the sweet potatoes into the slow cooker, then mix with another third of the sugar-curry mixture and all of the salt and pepper. Heat 2 Tbs. of oil in a 10-inch, heavy sauté pan over medium-high heat. When hot, add the ginger, lemongrass, and garlic, and sauté until softened, about 2 minutes. Add the final third of the sugar-curry mixture, plus the flour (and the remaining 1 Tbs. of oil if the pan is very dry), and cook, stirring, until no white flour is visible, no more than a minute. Add the coconut milk, pumpkin, lime juice, and stock, and bring to a boil over high heat, whisking vigorously to remove any lumps. Cook until smooth, thickened, and some bubbles appear, about 4 minutes. Pour over the sweet potatoes.
• 盖上慢炖锅，煮低，直到地瓜非常嫩，但仍保持其形状，大约4小时。搅拌盘并腌制的豆腐，盖上盖子，然后高高煮至碎屑变软，再过20分钟。立即服务。