Line a shallow baking tray approximately 20 X 30cm in size with baking paper.
To make the Polenta, use a medium-sized saucepan to bring 1 litre of water to the boil over high heat. Reduce the heat to low and gradually add the instant polenta in a thin steady stream, stirring constantly for 3 minutes or until the polenta boils and thickens (refer to the time specified in packet instructions). Remove the Polenta from the heat. Add the butter and season with salt to taste. Stir to combine. Use a wooden spoon or spatula to spread into the prepared baking tray. Refrigerate for a minimum of 2 hours to set.
Turn the Polenta onto a chopping board. Discard baking paper. Cut the Polenta into chips approximately 1.5-2cm thick and 10cm long.
Prepare a plate lined with absorbent kitchen paper. Place the chopped rosemary and sea salt into a small bowl.
Heat a medium sized saucepan with enough sunflower oil to reach a depth of 6cm. Ideally use a kitchen thermometer and heat to 180°C. Alternatively if you don’t have a thermometer, heat until a cube of bread tossed in the oil turns golden in 15 seconds.
Cook 4 of the Polenta chips in the oil for 8 minutes or until crunchy and golden brown. Use a slotted spoon to transfer the Polenta chips from the oil onto the prepared plate to drain. Repeat with remaining Polenta chips.
Note: Polenta chips can also be oven baked rather than fried. For oven baked Polenta chips, cook in 220°C conventional oven for approximately 30 minutes or until golden brown, turning halfway through cooking.
Tip: Avoid cooking more than 4 Polenta chips at a time, otherwise the Polenta chips will stick together. Should the Polenta Chips stick when cooking 4 chips, drain after 8 minutes cooking time and carefully use a knife to cut them apart while hot.
Transfer the Polenta chips to a serving plate. Sprinkle the chopped rosemary and salt mixture on top. Serve immediately – buon appetito!