Ba si di gua features sweet potato in a stretchy caramel sugar web. A spectacular family dessert with golden threads and sweet, fresh flavor.
Peel the sweet potatoes and cut them into thick batons, about 2x1/2 inches for bite-sized pieces.
Heat 2 cups of vegetable oil in a deep pan over medium heat to 340–350°F (170–175°C). Maintain steady heat for best texture.
Add the sweet potato pieces in batches and fry until golden and cooked through, about 6–7 minutes. Remove and drain well on a paper towel.
In a clean dry pan, combine 1 cup sugar with 2 tbsp water over medium-high heat. Stir gently until the sugar melts, then reduce to medium heat and cook to a light amber caramel without over-darkening.
Immediately add the fried sweet potato pieces to the hot caramel and toss quickly to coat. Arrange pieces on a lightly oiled plate, pulling sugar threads with chopsticks for the iconic web effect. Serve at once with ice water for dipping.