1.Place spatchcocks on a board, cut down both sides of backbones with poultry shears or sharp knife; remove backbones. Rinse cavity of spatchcocks; pat dry.
2.Combine spices, salt, pepper and oil in small bowl. Rub spice mixture over spatchcocks
3.Cook on heated oiled grill plate (or grill or barbecue), covered, 10 minutes. Uncover, cook a further 10 minutes or until cooked through.
4.Meanwhile make herb yogurt. Cook cumin and paprika in small frying pan, stirring, about 1 minute or until fragrant. Transfer to a bowl, stir in ginger, garlic, herbs and yogurt.
5.Serve spatchcocks with herb yogurt, lemon wedges and couscous, if desired.