For the seared polenta, place the cooked polenta into a bowl and season with salt and freshly ground black pepper.
Lightly oil a small square dish and press the polenta into the dish. Leave to cool - it will form a solid cake.
Heat the oil in a frying pan, slice wedges of the polenta from the dish and fry, turning frequently, until crisp and golden-brown on all sides.
For the stir-fried chilli broccoli, heat the oil in a wok or large frying pan, add the garlic and chilli and stir fry for one minute.
Add the purple sprouting broccoli and stir fry for 3-4 minutes, or until the broccoli is tender.
Add the lemon juice and season, to taste, with salt and freshly ground black pepper.
To serve, place the broccoli onto a plate with the seared polenta alongside.