Peel and dice the onion. Peel the carrot and cut into sticks.
Heat the oil in a pan on medium to high heat and fry the curry paste, onion cubes and carrot sticks in it for about 3 minutes. Add the lentils and broccoli florets, deglaze with coconut milk and stock and simmer with the lid on for about 15 minutes.
Roast cashew nuts fat-free in a pan on medium heat for 1 - 2 minutes and roughly chop.
Season the broccoli curry with salt and pepper and serve sprinkled with cashew nuts.