Put the marrow, greens and onion into a large saucepan with enough water to just cover. Bring to the boil and simmer for 5-10 minutes until the marrow starts to soften.

Add the blackeyed beans and heat through for about 5 minutes

Drain and put the marrow, greens and blackeyed beans back into the pan, add a glug of olive oil and lots of lemon juice to make a warm dressing. Season with salt if you wish. Adjust the lemon to your tastes - I love a lot of lemon on this one.

Best eaten warm, but fine to eat cold too!