This easy weeknight recipe is elevated by the crunchy pangrattato topping, which is one of my favourite things to make with leftover breadcrumbs (if you’ve got a packet of bought dry white breadcrumbs or panko, they’ll work perfectly here, too). The quickly cooked mushrooms, leeks and spinach sit in a lemony, creme fraiche sauce, making a lovely transitional winter-to-spring dish.
