Bitter chocolate and orange custard tart

Method

• 1
  Preheat the oven to 180C/160C fan forced and grease a 3cm-deep, 24cm (base measurement) fluted tart tin with removable base with coconut oil.
• 2
  Process the seeds and 1 cup of the oats in a food processor until finely chopped. Add the buckwheat flour, cacao, maple syrup, oil, orange rind and remaining oats. Pulse until a sticky mixture forms. Press over the base and side of prepared tin. Bake for 18-20 minutes or until dry and crisp. Cool completely.
• 3
  For the custard, whisk the egg, egg yolk, custard powder, cacao and maple syrup in a heatproof bowl. Bring the milk just to the boil in a saucepan over medium heat. Slowly whisk milk into egg mixture until smooth. Stir in the rind and 100ml orange juice. Return to a clean saucepan over medium-low heat. Cook, stirring constantly, for 8 minutes or until mixture boils and thickens. Remove from heat. Stir in the chocolate until melted. Cool over an ice bath, stirring occasionally, for 15 minutes.
• 4
  Spread the custard over oat base and place in the fridge for 4 hours or until set. Sprinkle with the extra rind and cacao nibs, if using. Serve immediately.