For the Bluberry Ginger filling
3 cups bluberries -fresh or frozen
1 tablespoon corn starch
1/4 cup sugar
1/4 tsp sea salt - fine
1 teaspoon cinnamon
1 teaspoon cardamom
1 1/2 tablespoons freshly grated ginger - about 1 inch peeled
1/4 cup Yuzu no Megumi
For Crisp Topping
45 grams rolled oats
45 grams almond flour - sifted
20 grams rice flour
45 grams dark muscovado sugar
45 grams red walnuts - broken into smaller pieces by hand
4 tablespoons butter. - melted
1 teaspoon cinnamon
1 teaspoon cardamom
large pinch of salt