Volcano Recipe

Rinse the sushi rice under cold water until the water runs clear. Drain and place in a rice cooker with 2.25 cups water and cook according to the cooker instructions (or simmer covered on the stove for 15–18 minutes, then rest 10 minutes).

While rice cooks, warm rice vinegar, sugar and salt in a small saucepan over low heat just until sugar dissolves. Do not boil. Remove from heat and let cool slightly.

Transfer cooked rice to a wide bowl. Gently fold in the vinegar mixture with a wooden paddle or spatula, fanning the rice to cool quickly until slightly shiny and room temperature. Cover with a damp cloth until assembly.

Prepare prawns: make 3 shallow diagonal cuts along the underside (to prevent curling), pat dry. Lightly dust each prawn with cornstarch and season with 1/2 tsp salt.

Make batter: in a bowl, combine tempura mix with cold sparkling water. Stir very lightly — lumps are fine; do not overmix. Keep batter chilled.

Heat vegetable oil in a deep pot to 180°C / 350°F (a thermometer is best). Dip each prawn into batter, letting excess drip off, then carefully slide into hot oil. Fry in batches 2–3 minutes until pale golden and crisp. Drain on a wire rack or paper towel. Keep warm.

Peel and very thinly slice or julienne the potatoes. Rinse in cold water to remove starch, then dry thoroughly in a clean towel.

Heat oil in a heavy pan to 180°C / 350°F. Fry potato strips in small batches until golden and crisp, about 2–4 minutes depending on thickness. Remove and drain on paper towel. Immediately sprinkle with salt and black pepper. Keep crisp until plating.

Dice sushi-grade salmon into small uniform pieces. Place in a bowl and add 3 tbs Japanese mayonnaise, 1 tbs sriracha, 1/2 tsp soy sauce and 2 tsp masago (if using). Mix gently to combine. Taste and adjust heat or mayo to preference. Refrigerate until assembly.

Place a bamboo mat on plastic wrap. Lay one nori sheet shiny side down. Wet your hands to prevent sticking and spread half the prepared sushi rice into an even layer over the nori, leaving a 1/2-inch strip at the far edge clear.

Flip the nori and rice so rice faces down on the plastic (optional for inside-out roll). Arrange 4 tempura prawns lengthwise across the nori, tails pointing toward the near edge so tails will show. Add a line of julienned cucumber and slices of avocado alongside the prawns. Sprinkle with toasted sesame seeds.

Using the bamboo mat, roll firmly but gently from the near edge, tucking as you go to form a tight roll. Seal the edge with a little water. Repeat with the second nori sheet and remaining ingredients to make 2 rolls total (or one large roll depending on nori size).

Using a sharp, wet knife, slice each roll into 8 pieces. Wipe the knife between cuts for clean slices.

Place about 1 to 1.5 tsp of the spicy salmon mixture on top of each sushi piece. Use a small spoon to shape it into a mound.

If you want the classic baked volcano finish: preheat a small broiler or torch. Lightly broil the tops for 30–60 seconds to just warm and slightly brown the mayo, or carefully torch until slightly charred. (Skip broiling if you prefer fully raw salmon.)

Drizzle each piece with unagi or teriyaki sauce and a little spicy mayo. Scatter thinly sliced green onions and a tiny pinch of masago or chili oil if using. Top each piece with a small nest of the crispy potato garnish for texture and to evoke the 'volcano' look.

Serve immediately with pickled ginger and wasabi on the side.