Step 1

Heat the oven to 180 degrees C

Step 2

In a large heavy bottomed saucepan, heat the olive oil

Step 3

Fry the onion until soft

Step 4

Add the garlic

Step 5

Add the beef mince an cook for a few minutes until brown

Step 6

Add the tomatoes, herbs and tomato puree

Step 7

Cook for 20 minutes

Step 8

Meanwhile, scoop out the middles of the marrow rings

Step 9

Place them in a large baking dish

Step 10

Spoon a portion of the mince sauce into each

Step 11

Distribute the remainder over the top of the marrow rings

Step 12

Cover with foil and bake in the oven for about 30 minutes

Step 13

Remove the foil, sprinkle with cheese and return to the oven uncovered for 10 minutes