This gratin is particularly nice and soothing. Don’t forget when cleaning the chicory to cut out the core at the base, which is the really bitter part of it.
Preheat the oven to 190°C/375°F/gas mark 5. Oil a large gratin dish with 1 tablespoon olive oil. Combine the chicory and spinach in the dish and season. Mix together the breadcrumbs and cheeses and sprinkle on top, then dribble the remaining oil over the surface.