In a food processor, pulse the dry polenta to make the granules less coarse.
In a medium saucepan, bring 3 cups of water nearly to a boil; slowly whisk in the polenta.
Add 1 more cup of water; stir; reduce heat to low and simmer for 15 minutes, stirring frequently.
The polenta should be creamy and not stiff; stir in additional water, if needed.
Remove from the heat and whisk in the olive oil and salt; cover and let stand for 5 minutes; season to taste and serve hot.
Coat a rimmed baking pan with non-stick cooking spray. Pour hot polenta into pan; use a spatula to spread evenly; level to top; cover and refrigerate until completely chilled and set, ~5 hours.
Turn contents out onto a cutting surface; cut into serving sized pieces; proceed to sear or grill.
