1. For the base, Line a 12-inch (30 cm) tart pan with baking paper and grease sides. Place nuts in food processor and blend until breadcrumb consistency. Add remaining ingredients and blend until just combined. Press into pan and place in freezer to set.
2. For the filling, preheat oven to 350°F (180°C) and roast sweet potato, whole skin on, for 30 minutes or until soft. Cut in half and squeeze out cooked sweet potato into blender.
3. In a medium saucepan, whisk coconut milk and agar agar. Heat over low to medium heat for 5 minutes, whisking to keep smooth. Dissolve corn flour in 1 tablespoon of water and whisk into coconut milk mixture. Stirring over heat for another 2 minutes until thickened.
4. Pour into blender with sweet potato and all remaining ingredients, and blend until smooth and creamy. Pour over base and top with roasted pecans. Place in refrigerator to set for 3 hours or overnight.
Photo courtesy of the author