Put chopped rhubarb in a bowl. Drizzle over honey. Add sliced strawberries and stir gently to mix.
Spoon fruit mixture into mini tart pans.
Add almond flour, buckwheat flour, coconut sugar, and salt to a food processor or blender. Add vanilla, almond milk, and crack eggs into food processor. Grate in lemon zest.
Process until smooth.
Pour batter over fruit in mini tart pans.
Bake in oven until top is golden, about 45 minutes.
Remove from mini tart pans.
Top with coconut cream (see recipe), and a sprig of mint.