Finely slice the leek and give it a wash. Finely chop the garlic.

Add the olive oil to a cast iron pot and cook the leek over medium heat for 10 minutes until softened. Add the garlic and thyme leaves and cook for 2 minutes.

Add the white wine, butterbeans, and chicken stock, then simmer for 10 minutes.

Meanwhile, heat a frying pan over high heat. Add the sausages and fry until browned, ensuring they are not cooked through.

Add the browned sausages and spinach to the bean mixture, then simmer for 20 minutes.

In the sausage pan with the remaining fat, add the breadcrumbs and toast for 5 minutes until golden. Season with salt and remove from the pan.

After 20 minutes, add the creme fraiche and parmesan to the bean mixture, along with the juice and zest of half a lemon. Season to taste with salt and pepper.

Spoon the stew into bowls, sprinkle with breadcrumbs, and serve.