Sweet potato candies (for 12)

1. Cut 550 g (20 oz.) sweet potatoes into 3 cm (1 1/4") slices. For a nice color, peel them fairly thickly (you will have 400 g / 14 oz. net). Soak the slices in water to remove their natural bitterness. 

2. Over high heat, cook the sweet potatoes in water in a covered pan.

3. While still hot, press them through a sieve; if you allow them to cool they will become gummy and difficult to sieve.

4. In a mortar, mash together the sweet potatoes and salt into a smooth paste. 

5. Wash 60 g (2 oz.) grapes in warm water; dry them well before adding them to the sweet potatoes and mixing.

6. Moisten a thin chakin or cotton cloth and wring it out well; spread it over the palm of your hand, place a ball of sweet potato on top, wrap it in the cloth and twist; this will create a cloth pattern on the ball that is one of its charms.

7. Remove the cloth. Top each ball with a grape for garnish. 

Sweet Potato Aspic Tart 

The principle is the same as using the cloth. After sieving the purée, simply add sugar and agar-agar to create a gelatinous consistency. Here we've added powdered green tea or matcha to create a two tone effect.