Preheat the oven to 400 degrees Fahrenheit. Line a shallow oven tray with foil. Tip the frozen sprouts out onto the foil lined tray and arrange in an even layer. Transfer to the oven to bake and thaw for 10 minutes.
Step 2
Remove the tray from the oven. Drizzle the olive oil over the sprouts and sprinkle over the salt and pepper. Return to the oven for a further 13-15 minutes to cook through and soften.
Step 3
Remove the tray from the oven and preheat a broiler. Roughly chop/ crush the cooked sprouts. Scatter the lemon zest, garlic powder and parmesan over the sprouts. Broil for 3-4 minutes or until browned and crisp at the edges and the cheese is golden. Serve hot.