Prepare the custard by heating up the milk in a medium saucepan over medium heat - steaming but not boiling.
In a medium bowl, whisk together the honey and arrowroot powder. Whisk egg yolks and salt in a mixing bowl and add to the honey and arrowroot powder.
While whisking the egg yolk mixture, pour the heated milk into the egg mixture in a slow stream to temper the eggs.
Pour everything back into the pot and heat it back up, stirring until it thickens for 4-7 minutes. Stir consistently so that it doesn’t stick.
Pour the custard into a bowl and add the butter and vanilla. Stir until combined.
Chill the cream in the fridge.
Prepare the tart dough by combining the flour, salt, sugar, and butter in a food processor or blender. Blend until it resembles fine crumbs.
Add the cold water a tablespoon at a time until the dough just comes together.
Divide dough in half, wrap in parchment paper, and freeze for 20-25 minutes.
After the dough has chilled, press dough out very thin with a rolling pin (about ⅛ of an inch) on a lightly floured surface.
Cut out the dough using a 4 inch flower cookie cutter.
Preheat the oven to 375 degrees F.
Grease two muffin pans with oil.
Very gently press the flowers into the muffin pans. Use your fingers and push the petal edges into each hole.
Refrigerate the flower tarts for 15 minutes, then poke each one with a few holes in the bottom of them.
Bake for 14-16 minutes, until golden brown.
Allow to cool for 20 minutes before removing from the pan. Be very gentle when removing them so the petals don’t break. Allow the tarts to cool on a wire rack.
Scoop the custard into the cooled tarts.
Top with your choice of berries and herbs.