Step 1: Start by cutting the ends from the marrows and put to one side. Use a spoon to scrape out the seeds and centre fibres.
Step 2: To make the stuffing, beat egg yolks and 2 egg whites together (keep hold of the other egg white, you’ll need it later on). Heat a little oil in a frying pan and pour in half the egg mixture to make an omelette. Cook for 3-4 minutes (or until firm). Remove from the pan to cool and do the same with the rest of the mixture. Then heat 1 tbsp of olive oil in a frying pan and cook onion, celery and carrot, add chilli powder after 2 minutes and then continue cooking for a further 3-4 minutes. Now add the beef and cook for a further 5 minutes, or until it browns. Remove from the heat to cool. Mix the egg white in with the meat and then cut up the omelette into thin strips and fold them through the meat.
Step 3: Split mixture into two and spoon into marrow shells, replace the tops (secure with a skewer). Place into a greased baking dish and bake at 180 C for 40-50 minutes, or until marrows are tender. Cut into thick slices and serve.
Step 5: This recipe is also great for stuffing other vegetables, such as peppers or courgette’s (they will cook a lot quicker but will probably be more of a side dish than main meal)