Heat the oven to 200C/180C fan/gas 6. Slice the courgettes into 1/2cm rounds using a mandoline or sharp knife. Heat the oil and butter in a large ovenproof pan or flameproof casserole dish over a medium heat and fry the courgettes for 8-10 mins until starting to brown.

Scatter in the herbs and bay and pour in the wine. Cook for a few minutes more until the alcohol evaporates, then tip in the beans along with the liquid from the can and the garlic. Nestle in the lemon halves. Pour over the stock and bring to a simmer, then cover and cook in the oven for 1 hr. Discard the bay leaves and lemon halves, if you like, and drizzle over the pesto, then scatter over the oregano leaves.