Preheat oven to 220°C/430°F (200°C fan).

Toss vegetables on tray with oil, garlic, herbs, salt and pepper. Spread out.

Roast 25 minutes, undisturbed (no flipping). Remove and cool for at least 5 minutes before using.

Lower oven to 180°C/350°F (160°C fan).

Grease & line pan: Spray a 19 x 30cm / 8 x 10" rectangle or 22 cm / 9" square pan lightly with oil, then line with parchment paper with overhang. (Note 3)

Egg mixture: Whisk eggs, cream, salt and pepper in a bowl.

Assemble: Spread 2/3 of the vegetables in the prepared pan. Pour over egg mixture, sprinkle with cheese, then top with remaining vegetables.

Topping: Top with crumbled feta, then mushrooms. Drizzle mushrooms with a touch of olive oil (makes it brown).

Bake: Bake 40 minutes until centre is just set.

Rest & serve: Rest frittata 5 minutes in the pan. Use paper overhang to lift out of pan, then slice into squares and serve.

Serving later: Cool on rack and remove paper from underneath (otherwise base gets soggy). Cut then refrigerate up to 5 days, or freeze. Reheat in microwave.