Step 1Preheat oven to 160°C and line a large, round baking tray with baking paper.
Step 2Place the stock in a large saucepan with 1½ cups of water and set over medium heat. Bring to a simmer, then gradually add polenta in a thin, steady stream, whisking constantly until well combined. Reduce the heat to medium-low. Cook, stirring, for 6–8 minutes, or until very thick. Remove from the heat and stir in chives and parmesan until well combined. Spread polenta to make a 24cm diameter circular base on prepared tray. Bake for about 18–20 minutes, or until light golden and set.
Step 3Meanwhile, heat olive oil in a large non-stick frying pan over high heat. Sauté the onion
for 5 minutes, or until softened. Add the mushrooms and sliced garlic and cook, stirring, for 3–4 minutes, or until golden. Season with cracked black pepper.
Step 4Scatter the mushrooms and sliced capsicum over polenta base, top with the crumbled feta. Return to the oven for 10 minutes, or until golden.
Step 5Meanwhile, combine rocket leaves and fennel in a salad bowl, and drizzle with balsamic vinegar. Serve polenta pizza topped with the rocket salad.