From Mark-Mi-Words's blog, with thanks.
Cooked this way they lose most of their moisture and become a thick, fragrant, chunky mass. They can be used as a pasta sauce (just add a little cream) or the base for a lovely soup (blend with a little stock and/or milk). They also make a great toast topping/ bruschetta, which is my favourite.
3 tbsp olive oil
3 garlic cloves, peeled and chopped
1kg courgettes, finely sliced
Salt and freshly ground black pepper
For the toast/bruschetta
6 slices of coarse country bread
1 garlic clove, cut in half
Extra-virgin olive oil, or butter
Parmesan, or other grateable cheese (optional)
Heat the oil in a large saucepan, then add the garlic, courgettes and a little salt. Cook gently, so the courgettes soften without browning. As they release their water, turn up the heat to bubble it off. When they become more concentrated and pulpy, turn it down again. Stir whenever they begin to catch on the pan, and do not allow them to brown more than a shade. Keep cooking until they are rich and oily, but not watery. Check seasoning.
Grill the bread, rub each side with garlic, and trickle with olive oil or melted butter. Pile a mound of the hot courgette mixture on top, grate over a little cheese, if you like, and serve.