Thank you all for your suggestions as to what to do with the monster zucchini. My favourite is this one from Sasa - "I vote keep it under the bed in case of intruders" - but it was great to be reminded about the merits of turning it into cake, soup, pie or stuffing it.
Yesterday I found something else to do with it (dismissing the suggestion from a colleague that the best place for it was the compost) - which means I can now turn the other half into cake. Or soup. Or pie. Sorry Sasa, I'll just have to beat off intruders with the rolling pin.
Slow-cooked zucchini and potato salad
I use the term salad loosely - this is the sort of thing you can eat hot or room temperature. It looks a little khaki in the photo, but I like to think that it has a sort of rustic, peasanty charm (and it tastes great).
2Tbsp olive oil
about 4 zucchini (or half a large marrow), cut into chunks
2 cloves garlic, finely chopped
1 onion, finely chopped
1 heaped tsp coriander seeds, lightly crushed
4-5 newish potatoes, cut into chunks
salt and pepper
Heat the oil in a heavy pot, then throw in the zucchini, garlic, onion, coriander seeds and potatoes. Saute for a minute or two over medium heat so everything is coated in the oil, then add a splash of water (maybe 1/4 cup?) and some salt and pepper. Cover with a lid, lower the heat and cook for about 20 minutes, until the potatoes are cooked. Remove to a serving dish and taste for seasoning. Drizzle with more oil and the lemon juice, then scatter over some chopped parsley. Best served at room temperature (we had it with lamb cooked on the barbecue and a green salad).