I have hellish memories of my mothers stuffed marrow and I've never come to terms with cooking and eating it as an adult.
If I was to find an overgrown courgette in the garden I might be tempted to cut in half lengthwise, scoop out the seeds with a spoon and leave it upside down on some kitchen roll to draw out the moisture. While that is happening soften a small, finely chopped onion in some olive oil when softened add a finely chopped clove of garlic and some pinenuts; keep cooking until the pinenuts and garlic have a little colour. Leave to cool and add some fresh breadcrumbs, chopped mint and crumbled feta, season with pepper and a little salt.
Whack the marrow in a hot oven with a little oil drizzled over, after 10-15 mins top with cheesy onion mix, turn the heat down and wait until the topping is golden.
Then throw it in the bin and order a takeaway.