Sticky orange and semolina pudding with rose custard

Name: Sticky orange and semolina pudding with rose custard
Prep time: 25 min
Cook time: 1 h 10 min
Total time: 1 h 35 min
Cuisine: Moroccan
Ingredients: 225g thick Greek-style yoghurt; 1/4 cup (55g) caster sugar; 100ml light olive oil; 2 eggs; 2 oranges, (both finely zested, and 1 orange peeled and thinly sliced); 160g fine semolina; 1/2 cup (75g) self-raising flour; 1 tsp baking powder; 1/2 tsp ground cardamom; 1/2 cup (50g) almond meal; Chopped pistachios, to serve; Dried rose petals (from gourmet food shops), to serve; Juice of 1 orange; 125g caster sugar; 2 tbs Grand Marnier (substitute other orange liqueur); 8 egg yolks; 1/2 cup (110g) caster sugar; 2 cups (500ml) milk; 1 vanilla bean, split, seeds scraped; 2 tsp rosewater