Grease 23 cm loose-bottom tart tin with coconut oil and set aside.
Place oats, nuts and buckwheat groats in a food processor and mix until coarsely ground. Add maple syrup and coconut oil, then add dates and process all together until the mixture resembles wet sand texture.
Firmly press the crust mixture into the bottom and sides of the tin, then place in the fridge, while you prepare the filling.
To make the filling:
Peel the peaches and cut into smaller pieces. Place them together with the lemon juice in a food processor and blitz until smooth.
Pour the coconut milk into a medium saucepan, then add peach puree and maple syrup and stir together. Add arrowroot powder and agar powder and keep stirring until both have completely dissolved. Bring to boil and allow to cook for approx. 1 minute. Remove from the heat.
Using a metal sieve, strain the filling mixture into a small bowl, then transfer it to the tart base. Place in the fridge for at least 4 hours or overnight. Decorate with fresh peach slices, raspberries and strawberries. Enjoy!