1. Preheat your oven to 220°C.
2. Make the crust. Bring the vegetable stock to a boil and whisk in the polenta. Add the rest of the crust ingredients and keep on stirring until thick and creamy, about 3-5 minutes.
3. Let the polenta cool and set in the refrigerator for ½ an hour. Spread on a baking sheet in a 1 cm thick layer. Bake the polenta crust in the oven for 20-25 minutes, until edges start to crisp.
4. Saute the onion and mushrooms in the olive oil for 2-3 minutes, add the spinach and let wilt. Season with salt and pepper.
5. Spread the cream cheese on top of the slightly cooled polenta crust. Top with the sauteed spinach mixture. Add the cherry tomatoes and Castello® Traditional Fetta Cubes in Brine.
6. Bake in a 220°C oven for 10 minutes, then serve!
Top the pizza with tomato sauce instead of cream cheese, if you prefer.