Place macadamias in the bowl of a food processor and process until smooth. They can still retain some texture. Add cheese, egg and flour and process until the mixture forms a ball.
Remove from the bowl and sprinkle with your choice of flavouring. Gently knead to incorporate the flavouring and roll dough into a 4cm diameter cylinder. Wrap in baking paper or plastic wrap and refrigerate for 30 minutes.
Preheat oven to 180°C. Using a sharp knife, slice the dough into discs just less than 1cm thick. Place the discs 3cm apart, on a large baking tray lined with baking paper.
Bake for 10-12 minutes, until biscuits are golden on the edges and underneath. Using a metal spatula, remove each biscuit and place on a wire rack to cool before serving.
Biscuits can be stored in an airtight container for up to 4 days.