Preheat oven to 180°C or 160°C fan forced. Line a tray with baking paper. Place pumpkin on prepared tray. Drizzle with 2 tablespoons of olive oil and season with salt and pepper. Roast for 25 minutes or until lightly golden and tender.
Heat a frying pan over medium to high heat and add 1 tablespoon of oil. Cook shallots and kale for 3 minutes or until wilted. Add brown rice, cashews and ¼ cup water. Stir until heated through.
Take frying pan off heat and cool slightly. Add pumpkin pieces, egg and cornflour, and mix to combine.
With wet hands form ½ cup scoops of mixture into 8 patties.
Heat frying pan over medium to high heat with remaining oil. Cook patties in 2 batches for 3-4 minutes each side or until golden.
Serve topped with sour cream, rocket leaves, sweet chilli sauce and lemon wedges.
Go Vegan: Substitute egg with chia seed mixture – 1 tablespoon chia seeds soaked in 3 tablespoons of water. Replace sour cream with coconut yoghurt.