1.Bring the water and salt to a boil in large saucepan; add polenta. Reduce heat; simmer, stirring about 15 minutes or until polenta is very thick. Polenta can be served at this point, piled onto a plate, or continue as below.
2.Press mixture into oiled 18cm x 28cm rectangular slice pan. Cool to room temperature; refrigerate until firm. Polenta can be made 1 day ahead to this stage and refrigerated, covered.
3.Cut polenta into 12 rectangles. Heat oil in large frying pan. Cook polenta until browned lightly and crisp both sides; drain on absorbent paper.
4.Serve polenta on a plate, garnish with curled spring onions if desired.