Roasted Sweet Potato, Avocado and Pickled Onion Maki

Prepare the rice

1. Rinse the rice in several changes of water, stirring gently with your fingers, until the water runs almost clear. Drain it in a colander for 10 minutes.
2. Put the drained rice and the 360 ml of water in a small heavy-bottomed pot with a tight-fitting lid. Let it soak for 20 minutes. Use this time and the cooking time that follows to prepare the onion and the boniato.
3. Cover the pot and heat over medium heat until it starts to boil gently. Lower the heat to the minimum and cook for 13 minutes without lifting the lid. Remove from the heat and let it rest for 10 minutes, still covered.
4. Mix the 45 ml of rice vinegar, the 15 g of sugar and the 4 g of salt for the seasoning. Warm them gently, just until the sugar and salt dissolve. Spread the freshly cooked rice in a wide, shallow dish, pour over the seasoning and mix it in with cutting and folding motions, without crushing the grains. Fan it or stir gently until it loses its strong heat and is just warm.

   

Prepare the onion, the boniato and the mojo

5. Dissolve the sugar and salt for the pickle in its 45 ml of vinegar and 45 ml of water. Add the thinly slivered onion, mix and let it sit for 20 minutes, stirring once. Before assembling, drain it very well and pat it lightly dry with paper towel. Discard the pickling liquid.
6. Heat the oven to 200 °C, with top and bottom heat. Toss the boniato sticks with the 10 ml of oil and 1 g of salt. Spread them out on a lined baking tray without crowding them and roast for 20 to 25 minutes, turning them halfway through. They should be tender when pierced and hold their shape. Let them cool before assembling the rolls.

   

7. For the mojo, gently warm the 15 ml of oil with the garlic for about 1 minute, without letting the garlic brown. Remove from the heat and let it cool slightly before adding the sour orange juice and the pinch of salt. Set aside in a small sauce jug.
8. Cut the avocado into strips. Divide the rice, boniato, avocado and drained onion into four portions to share among the rolls.

Roll and serve

9. Place a sheet of nori on a bamboo mat, shiny side down and with a long side facing you. With slightly dampened hands, spread a quarter of the rice in an even layer, leaving about 2 cm free along the far edge.
10. Arrange a quarter of the boniato, avocado and onion in a line across the third of the rice closest to you. Lay the sticks along the length of the roll, filling in the gaps, without piling them up too much.

    

11. Lift the edge of the mat closest to you and wrap the filling with the nori and rice. Keep rolling with gentle, even pressure, pulling the mat away as you go. Lightly dampen the free edge of the nori to seal. Repeat with the other three sheets.
12. Leave each roll seam side down for 1 minute. Cut it in half and divide each half into four pieces, to get eight pieces per roll. Wipe and lightly dampen a very sharp knife between cuts. Serve right away with the mojo on the side.