4 cups / 350 g green beans, trimmed and cleaned
7 oz / 200 g button mushrooms
1 1/2 tbsp all-purpose flour
1 cup / 240 ml (2 1/2 dl) half and half
1/4 cup / 20 g panko breadcrumbs
1/4 cup / 30 g freshly grated Parmesan cheese
1 cup / 30 g chopped fresh parsley
1/2 tsp ground black pepper