Halve the broccoli and sprouts. Place on an oven tray and cover with the olive oil and rosemary. Generously season with salt and pepper. Place in a 250˚c oven for around 20 minutes or the vegetables start to brown.
Meanwhile make the dressing. Juice and zest the half a lemon into a small container or jug. Combine the mixture with the mustard and olive oil. Then season to the dressing to taste.
Remove the broccoli and sprouts from the oven and combine with cooked cannellini beans and dressing. Mix well to allow the dressing to cover the vegetables evenly.