Brush two 22 x 30cm baking pan with olive oil to lightly grease.
Bring the water to the boil in a sauce pan over a medium-high heat. Gradually add the polenta in a thin steady stream, whisking constantly until all the polenta is incorporated into water. Reduce heat to medium and cook, stirring constantly with a wooden spoon, for 2 minutes or until mixture thickens and polenta is soft.
Pour the polenta evenly over the base of the prepared pan and use the back of a spoon to smooth the surface. Cover with non-stick baking paper and set aside to cool. Place in the fridge for 2 hours to set
Turn polenta onto a clean work surface. Use a sharp knife to cut off the curved edges. Cut lengthways into 2cm strips. Cut each strip into 8cm-long pieces.
Add enough oil to a large heavy-based saucepan to reach a depth of 6cm. Heat to 180C over high heat. Add one-sixth of the polenta chips and deep-fry for 5 minutes or until golden brown. Use a slotted spoon to transfer chips to a plate lined with paper towel. Repeat, in 5 more batches, with the remaining polenta chips, reheating oil between batches.
Transfer polenta chips to a serving platter. Season with salt and pepper. Serve immediately.