Preheat oven at 200°C.

Cut the marrow into chunks about 2cm thick. Take a cookie cutter and remove the soft flesh and seeds from the middle of each piece creating 4 rings.

Mix olive oil and salt in a mixing bowl and rub into the rings before laying flat in a sheet of baking parchment. Cook for 20 mins turning once.

Transfer each ring to a plate. I added a little more leftover risotto and sprinkled nutritional yeast to serve.