Method

• 1.
  Grease six 200ml ovenproof dishes. Sprinkle breadcrumbs into dishes. Gently warm the milk, cream, lemon zest and unsalted butter in a saucepan over low heat. Beat egg yolks with 60g sugar until pale. Stir in milk mixture, then pour over breadcrumbs. Soak for 15 minutes.
• 2.
  Preheat oven to 170°C. Place dishes in a roasting pan and pour in enough hot water to come halfway up sides of dishes. Cover pan with foil and bake for 20-25 minutes until just set. Remove dishes from pan and cool (this can be done up to 1 day in advance; keep refrigerated).
• 3.
  When ready to serve, whisk eggwhites until stiff peaks form. Gradually beat in remaining 70g sugar until thick and glossy. Spread 1 tablespoon lemon butter on top of each custard, pile eggwhites on top, completely covering base and bake for 6-10 minutes until light golden.