In a saucepan on high heat, place sushi rice into 1 ½ cups of water. Cover the saucepan and bring it to a boil before reducing the heat to low and cooking until rice is soft and has absorbed the water. Remove from heat.
Combine cooked rice with vinegar in a bowl and stir to prevent rice from becoming clumpy.
Place 1 nori sheet on a sushi mat with the shiny-side facing down. Spread a quarter of the rice mixture over the nori sheet and make sure you leave a border that’s roughly 3cm wide along the edges.
Place one-quarter of the avocado along the edge facing you. Top with one quarter each of the salmon, cucumber and carrot.
Using the sushi mat, roll up the filling and repeat with remaining ingredients.
Slice each roll into bite-sized pieces. Serve with soy sauce.