Heat the oil in a large, heavy-based saucepan over a medium heat. Cut the fennel into quarters lengthways, remove the tough middle and slice each quarter into 3 wedges. Add to the pan and fry for 4–5 minutes or until beginning to soften and colour. Add the shallots and garlic and fry gently for a further 4–5 minutes or until softened and lightly golden.
Stir in the Pernod, white wine and chopped herbs and bubble for 1–2 minutes or until almost evaporated. Add the courgettes and green beans and stir well.
Add enough stock to almost cover the vegetables and scatter with the olives. Bring to the boil, then reduce the heat, cover and simmer gently for 8–10 minutes or until the vegetables are almost tender. Stir in the tomatoes and basil leaves and simmer for a further 3 minutes. Season to taste with salt and pepper.
Place a small, nonstick frying pan over a high heat and add the bacon, if using. Fry for 3 minutes or until crisp. Remove with a slotted spoon and drain on kitchen paper.
Ladle the stew into bowls and scatter with the crispy bacon, if using. Serve with warm, crusty bread, if liked.