In a pot, bring 1 1/2 cups of water to a boil, then add the dry polenta. Reduce to low heat, stirring, for 3-5 minutes until water is absorbed. Allow it to cool for about 10 minutes as you mix in the spices and nutritional yeast.
Spread the cooled polenta mixture on a parchment (or silpat) lined baking sheet. It will be very sticky (I used my fingers to shape it, but you can use a rubber spatula).
Now top the polenta crust with the prepared toppings. Place in the oven and bake for 20 minutes.
Remove, let cool just a bit, and serve. This is great eaten hot or cold!