Preheat oven to 160C.
For the crust, add the coconut and sunflower seeds to a food processor and process until there are no more whole sunflower seeds and it reaches fine crumbs.
Add the syrup and oil and process until combined. Press crust into the base and bottom of a lined tart tin, making sure there are no gaps and the crust is as even as possible. (I used an 18cm wide and 4cm deep tart tin).
Bake the crust in the oven for 15 minutes or until the edges are golden brown. Set aside and cool.
For the mandarin curd, remove the seeds and white strands of the mandarin segments.
Add to a medium-sized saucepan with the coconut cream, syrup, cornflour and agar agar powder. Puree all ingredients with a whizz stick until there are no strands of mandarin and all of the powder is fully incorporated. Bring the saucepan to a gentle boil for 1 minute then reduce to medium heat while stirring until thickened. Remove from the stove. If the mixture has become lumpy, use the whizz stick to puree the mixture.
Let the mixture cool for 10 minutes then pour into the tart tin. Let the tart cool at room temperature for 1 hour then set aside in the fridge. The tart is ready when it is dry and slightly firm to the touch.
For the decorations, remove the seeds and the white strands from the mandarin segments. Slice along the grain of the mandarins and arrange on your tart.