Step 1

Whisk eggs in large jug with fork until combined, season.

Step 2

Spray large wok with cooking oil; heat on medium-high. Pour one-third of egg mixture into wok, swirling, to make a large, thin omelette; cook until set. Slide omelette onto sheet of baking paper. Repeat with remaining egg mixture to make two more omelettes. Cool.

Step 3

Meanwhile, place spinach in large microwave-safe bowl; microwave, covered, on HIGH (100%) about 2 minutes or until wilted. When cool enough to handle, squeeze out excess moisture from spinach.

Step 4

Finely chop prosciutto. Peel and crush garlic. Combine prosciutto, cheeses, garlic and spinach in medium bowl.

Step 5

To assemble, slightly overlap two omelettes to form a rough rectangle. Halve the remaining omelette; place over the rounded lower halves of other omelette to reinforce. Fold in the sides to make a rough rectangle.

Step 6

Spoon cheese mixture down long edge of rectangle closest to you; roll up tightly to enclose filling. Place, seam-side down, on board; slice into six pieces.