Yam Tempura Roll (6 Pcs) Recipe

Prepare yam

Peel the Japanese sweet potato and cut into uniform batons about 1/4 inch thick and 3 inches long. Pat dry with paper towels to remove surface moisture.

Make batter

In a small bowl, combine 1 tablespoon all-purpose flour, 2 tablespoons cornstarch, 1/2 teaspoon baking powder and 1/4 teaspoon salt. Add 3 tablespoons ice-cold sparkling water and stir lightly with chopsticks or a fork just until combined — a few lumps are fine. Keep the bowl over ice or add a couple of ice cubes to the sparkling water to keep the batter very cold (this gives a lighter, crisper tempura).

Heat oil

Pour about 2 cups of vegetable oil into a small deep pot to a depth of 1.5–2 inches. Heat over medium-high until the oil reaches 350°F (175°C) or a small bit of batter dropped into the oil sizzles and rises immediately.

Fry yam

Working in a single layer, dredge the yam batons lightly in a dusting of additional flour (reserve extra flour if needed), then dip into the cold tempura batter to coat. Carefully lower into hot oil and fry 2–3 pieces at a time to avoid crowding. Fry 2–3 minutes until the batter is crisp and the yam is cooked through and tender when pierced with a skewer. Remove to a paper towel-lined tray to drain. Repeat with remaining yam. Keep warm.

Prepare sushi rice (if not already)

If your sushi rice is not yet seasoned: in a small bowl, mix 1 tablespoon rice vinegar, 1/2 teaspoon sugar and 1/8 teaspoon salt until dissolved. Fold this seasoning into 1 cup of hot cooked short-grain rice, then fan or cool the rice to room temperature. Spread the rice out to help it cool evenly.

Prepare nori and rice

Place 1 full nori sheet shiny side down on a bamboo mat or clean working surface. Wet your hands lightly with water to prevent sticking. Take about 3/4 cup of sushi rice (adjust to fit nori) and spread it evenly over the nori leaving a 1/2-inch strip at the far edge free to seal. Press rice evenly but not too firmly.

Add fillings

Along the near edge of the rice (closest to you) place 3–4 pieces of the tempura yam in a line across the width of the nori. Dot 1 tablespoon mayonnaise along the yam (spread lightly) and sprinkle 1/2 tablespoon toasted sesame seeds over the rice. Optionally add a few thin slices of green onion on top of the yam.

Roll

Using the bamboo mat (or fingers), lift the near edge of the nori and rice up and over the fillings, tuck tightly, and roll away from you to form a tight cylinder. Apply gentle pressure to compress the roll evenly. Seal the far edge with a little water if needed.

Cut

Using a very sharp knife moistened with water, cut the roll into 6 equal pieces. Wipe the knife dry or moisten between cuts to keep clean, for neat slices.

Garnish and serve

Arrange the 6 pieces on a plate. Drizzle 2 tablespoons eel sauce (mix with 1/2 teaspoon sriracha if you want a spicy-sweet finish) over the rolls or serve the sauce on the side. Sprinkle remaining sliced green onion and an extra pinch of toasted sesame seeds over the top. Serve immediately while tempura is crisp.

Make sure the tempura and rice are cooled to near-room temperature before rolling so that the nori doesn't become soggy. If making ahead, fry tempura and keep uncovered briefly on a rack to preserve crispness; reheat very briefly in a 350°F oven for 3–4 minutes before assembling if needed.